Well, I can help you some anyway, and then hopefully others will chime in, too....
First of all, I have a feeling your biggest issue is going to be keeping the fish you want in an 80 gallon tank. You shouldn't really have more than about 16 inches of fish in there total (and that's full grown).
1. filter--you can get by with no filter if you have a really good protien skimmer
2. as for a protein skimmer, I would highly recommend an ASM brand--I have one and it is great. Others on here will also recommend CPR bac pak (for Hang on)
3. Lighting in your case is not an issue unless you plan on having corals--in which case it depends on the type of corals you want as to the lighting that you need.
4. Yes, chillers are expensive, and I don't have one and have no clue about them--sorry.
The are a ton of other things you might want, too. It would be higly helpful to read all of the articles on this site about getting started--fishless cycling, etc.