My personal opinion if you want to keep it simple the LR
would be the easiest.. It provides your benificial bacteria and well as does your filtering for you.. If you looking money wise and are determined not to use LR
then you are going to need some sort of biological filter.. My personal opinion would be a wet/dry filter.. It would provide a decent bacteria bed and could be converted in the future to be a sump when/if you decided to add LR
What fish can I keep in this way
I would say that as long as you had room for hiding and such you should be able to keep just about anything as long as they did not feed from the LR
.. A few suggestions without taking tank size into consideration would be the common puffers, Lionfish, Triggers, Eels, clownfish, tangs, butterfly fish, Ect.. there is a wide assortment but it would all depend on if you wanted agressive fish, community fish ect...
The LFS owner told me its not advisable to keep marine fish without LR
It would be ok and is a pretty common setup among beginners however it is Much easier to maintain a tank when your LR
is doing 99.9% of the filtering of all the bad wastes.. There are many ppl out there that are doing FOWLR
tanks and have no corals at all.. The have a good basis for when/if they wanted to add corals later down the road.. Believe me you may not want corals now but there are many out there that will be extremely tempting...