Fish Only With Live Rock

Your biggest cost would be a quality skimmer, you're wouldn't need super expensive lighting.

 

I don't use a skimmer. I strictly us a algae scrubber from turbo aquatics. Have a 240 gallon display with a shark, lion fish, eel, grouper and wrasse. Some of the messiest fish out there. I have little to no problems with algae and have metal halides. That is good so something you might look into.

 

Bigger is better. Start with the 60 gallon tank. Volume will buffer your mistakes. Surface area is your friend. Don't stock the tank too fast. Research compatibilities of fish and critters before you by them. Many fish are fairly tolerant to nitrates than coral so filtration can be less than what a reef tank needs. 200 micron filter sock/s or even 100 micron and a settling area in a sump work well to collect detritus. Clean the filter sock/s regularly. There are almost as many opinions as people out there, but mine is size the skimmer to your system. If you decide to make a bigger system later, get a 2nd skimmer at that time, you would be able to clean them on alternate schedules so you would have more consistent skimming. I hear good about algae scrubbers as a way to export nutrients. I've been thinking about building one for fun. Currently I grow algae in a sump then export nutrients by periodically removing some of the algae. It's a great hobby. Welcome to the reef side!

 

I started off with a FOWLER even though I didn't realize what FOWLER meant until recently. I had a 75g with some sand and minimal rock. 2 clowns which I still have. I have added more LR and LS. I have gone through countless inverts for cleanup crews because I do not have many fish. I am in the process of getting rid of some nasty RBA and hopefully for that last time. I will be adding another cleanup crew as well as a few fish while trying the more is better theory. Power heads are important, different sizes to prevent dead spots, or @ least that is what I am doing to my tank now. Far as light if your hopes are ultimately to go to a reef setup then get yourself a light @ the beginning that will handle enough watts per gallon while being used with the reef tank in the future and only use half when doing the FOWLER tank. Otherwise you will be buying another light to add to your existing light or buying a whole new light and they are not cheap. I have added a pumped top off system for evaporation but if your tank has room above it you could go with a gravity TO. Ramora pro on the skimmer with a preskim box. Plan on converting my HOB carbon filter to a cheato/HOB refugium.