Those levels are looking good. Now that ammonia is at 0 and your nitrites are starting to level out, you now need for the nitrites to be at zero. It sounds like a week would be a good guesstimate, just make sure you test before purchasing. The Nitrates should be less than 20pmm. Your damsels should be fine if they have made it this long. They should also be able to make it back to the fish store as well. I'll tell you, that is the first fish ALL LFS
want to sell you but with them being somewhat agressive, it doesn't make for a good 'first' time fish from what I have found. I had to take mine back as well.
For your friend since you are past this point, tell them to put a raw shrimp (from the grocery) in the tank and that will speed the process along a bit faster. It won't help you any as it sounds like you are coming to an end of the cycle. Yippie! I couldn't hardly wait.
The 'cleanup crew' as they call them (the hermit crabs and snails) are pretty fun to watch believe it or not. Just don't let them talk you into emarld crabs or the ones that have 2 claws. Only get hermit crabs. The others can be opportunists and grab your fish for dinner. Another lesson I learned the hard way. LOL.
For the lights, I'm not sure if that would be too much or not. Anyone else have any ideas? I know they sell 18" bulbs that are actinic or 10k, I just looked at those today for my QT and they were cheap.
Oh, I forgot to mention a good website when making your fish list. It is
. It tells you some good info if the fish are peaceful, semi-agressive, or agressive. It helped me alot. There was also an article I read today that had compatible fish with the yellow goby. I can post those fish tomorrow if you would like.