Hey Neilanh!
I'm not sure if continueing to add ammonia is a good idea. Granted, I have never done a fishless cycle with FW. This is what happened when I cycled my tanks. First the ammonia would spike, then the nitrites would spike, then the nitrates. Once my ammonia and nitrites were at 0, and my nitrates were at 40 or below, I started to stock the tank.
I start with the hardiest fish first and add 2-3 small (1 inch) or 1-2 medium size (more than 1 inch) at a time. But of course, this all depends on what type of fish you're putting in there. If you have any super sensitive fish, only put in one at a time. I wait at least a week and a half before putting more fish in. Always monitor water conditions closely when stocking the tank. If you start to get ANY ammonia or nitrites, STOP STOCKING and wait till levels go back to normal. If your nitrates start to get high, you're probably feeding too much. Until the tank is fully stocked, I only feed every other day.
With stocking your tank.....
The basic rule of thumb for FW community tanks is to never exceed 1 inch of fish per gallon. When picking fish to stock the tank, always find out what their full grown adult size will be. Most fish stores have babies in thier tanks. The only fish that will stay approximately the same size are guppies, and some tetras. The best way to find out their adult size is to get a book that breaks down individual species. As I mentioned before, alot of people employed at the LFS are not informed or experienced aquarists, and they will not give you correct information. I can't tell you how many times I have asked questions and got ridiculously wrong answers from pet store employees. Even the little charts they have on the tank are wrong.
As far as your wish list, that is too many fish for your size tank. I calculted your adult sizes and it's almost 60 inches of fish. Most gobies are either brakish or saltwater. I'm not familiar with the species you mentioned, but I'm willing to bet it's a brakish fish, which is a completely different type of tank. Scratch that one off the list. Mollies do better with salt, but they may be able to live without it. To avoid all problems I would just scratch them off the list too. Platies and swordtails look alot like mollies, and don't require the special attention. Go with those as a substitute. Alot of fish are very sensitive to salt, even in small amounts; especially catfish. The corydoras are catfish and the salt can cause health issues, which you don't want. I would stay away from all species that require any amount of salt.
I have never kept snails, nor would I. From what I understand, the only type of system where they are of any benefit, is in a pond. They reproduce like crazy, and can eat all the beneficial bacteria in your tank, causing serious, if not lethal water parameters. I would scratch them off the list too. The corydoras and loaches will take care of any leftover food on the gravel. That's really all the scavenging you need. You will have to do frequent pwc in order to maintain water quality. All that stuff people tell you about plecos taking care of the algae and scavengers is really unnecessary. I have plecos in every one of my tanks, and they don't eat the algae. I still have to clean it with a brush. PWC and an occasional glass cleaning with an algae brush (i.e. magfloat) is all you need to keep the tank up to par.
The bosemani rainbows can get large and bully other fish. With the tetras, I would choose only one group because you will have a nicer schooling display. If you get two different species, they may not school together. Stay away from killifish, they require special care. I had 2 killifish and the male harrassed my female to death and then proceeded to harrass every other fish in the tank, big and small, until I removed him.
I would go with
1 male swordtail 2 inches
2 female sword tails 4 inches
3 corys 7 inches
1 tiger pleco 6 inches
2 yoyos 4 inches
5 rummynose tetras 7 inches
Add these fish in this order, waiting at least a week and a half between add ons and you should be fine. With the tetras, it is recommende to have at least 5 for a schooling species. I have found that it is best to add schoolers at the same time. I put them last on the list because by the time you put them in, your tank should be well established and able to handle 5 fish at one time.
Next to the fish is their total adult size. If you go with this plan, (I tried to go as close to your preferences as I could) your total will be 30 inches of fish. Which will leave you with 15 inches to play with. By the time you finish this stock, I'm sure you will run into many species that will peak your interest and you will fill in the 15 inches in no time.
Here are some other suggestions that will be compatable with the above suggested stock.
A school of hatchetfish (you could also sub these for the rummynoses)
A butterfly fish 3 inches
2-4 platies 2 inches each
2-5 furcata or celebes rainbows 2 inches each
khuli loaches 3 inches each
fancy guppies 1 inch each
A school of harlequin rasboras (can substitute for the rummynose)
1 upside down catfish 3 inches note* if you decide to go with one of these, make sure it is not one that gets huge. There are only two species that stay small. The others get 6-10 inches and will have the rest of your tank for lunch.
Twig catfish 6 inches
Banjo catfish 4 inches
Hope this helps and keep us posted!!