I don't know much about the megans, FK, or Ksport, (all junk) but the Bilstein, (PSS9?) KW, and H&R aren't really "coilovers", they're matched systems that would take some re-working if you wanted to change springs and in some cases ride height. (but are also good and relatively cheap compromise setups)
Pretty much anything from GC on up are real "coilovers", and to greater or lesser extents can be what you want them to be in terms of street or track use. The more expensive stuff on the list (AST, JRZ, Moton, Ohlins) are more capable of handling higher spring rates, and so they're more track-capable, but that doesn't mean they're less streetworthy, just that it's difficult to justify the expense in a non-competitive use. Most of them, being higher quality systems, are going to have the effect of making stiff springs more comfortable on the street. Or at least, I know the ASTs and Motons will, (and of course both of those have two different lines of dampers with different internals and price points) not totally sure about the JRZs or Ohlins, they may just be valved off the shelf for way too high of spring rate to be street-comfortable, I couldn't say, they're more popular among the club racing crowd.
The GC and TCK are koni-based, and so they'll be relatively comfortable with anywhere from stock to compromise (400 lb?) spring rates, but get less capable of keeping things comfy as the spring rates climb.
Picking the right dampers is tricky, and so that's why TxZHP was asking about use and budget. If you want something that can grow with you as you move from strictly street use into light and then competitive track use, the AST 4100 is a good choice at a good price. If you see your track time being more occasional and less competitive, the KWs, PSS9, or H&R cup kit setup might work well. If you've got money to burn, get yourself some AST 5100s or Motons, and they'll be plenty capable in whatever you want them to do.