My thought on humidors is to definitely go as large as you can afford, whether a humidor or a home-made coolidor. Once you get into it, even on a tight budget, you will find yourself building a nice inventory quite fast.
I found a new cheap humidor on ebay for $20 and the delivery was about the same, but it can hold about 150 sticks. Although it was cheap it looks great and works really great too, not counting the hygrometer (which is a whole new ballgame that you will find out about along the way)
Note: whatever the number of cigars a humidor claims to hold, you have to reduce that number by sometimes as much as half. Mine advertised 300 HA! I think they mean if all the cigars are piled on each other using up every square inch. I have a humidor for aging, looks, and easy access. I have a huge coolidor for storage which is pretty much maxed out and now I'm working on making a very large humidor/storage from an antique chest.
Online purchases companies I've been happy with:
cigarinternational.comjrcigars.commikescigars.comfamouscigars.comtntcigars.comcigarbid.comThere is a host of other companies out there but the ones mentioned above are a good place to start. If you price shop between and sign up for their newsletters and specials, then you will pretty much get the best deals going. Most of these site offer humidors and accessories for sale too.
Coolidors are very easy to maintain.
Latches and dividers, whatever works for you I guess. As long as the humidor is as airtight as possible (when you drop the lid it should not slam shut but instead, make a short whoosh sound)
Good Luck and have fun with it. GO BIG GO BIG GO BIG, you won't regret it.
Pete