Let see 5 gallon planted - rimless. Here's some very basic suggestions.
An HOB would probably ruin the effect of a rimless. I picked up a Tom Rapids Mini canister and after having a little flood (my mistake) it's been working fine. It sits well behind a small tank and offers a ton of filtration for it's size. Pretty darn cheep as well. The tiny spray bar is really kind of fun.
For substrate I'd stick with sand or a decent soil type mix (eco-complete, etc). I accidentally found that a thin layer of gravel over sand works really well. It really helps to keep everything planted and makes cleanup easier.
Lighting - I'd do ~20 Watts of florescent over it. That should be plenty to grow most things.
Research your plants carefully. Many pet-stores sell terrestrial plants as aquatic. Before you spend the money double check.
Fertilizer - Buy some dry fert's and mix them with water yourself. This runs about 100 times cheaper than buying the liquid ferts at the petstore. Online is the way to go.
CO2 - leave it alone for now. This is can be deadly to all fish in a tank if you are not careful. Plants grow fine without it, just slower.
Fish - well if you've done salty, you can figure this one out yourself
Cleanup Crew - Malaysian Trumpet Snails
Water parameters - if possible get fish to suit the water you'll be using instead of trying to match the water to the fish. Test the water source you'll be using and then research out what likes that type of water and will live happily in a tank that size. With fresh water once the nitrogen is all going to nitrate you pretty much don't have to worry about it anymore. Especially if the tank is planted.