Could I mine the most prominent alt coin and exchange them for BTC? What type of mining equipment is needed for mining alt coin?
litecoin is about 3 years behind bitcoin... and really isn't ever going anywhere beyond that - when someone gets around to making an fpga or asic for it it will all fall apart.
From a "mine it and immediately sell for btc" perspective it's possibly to make some money there... I know some guys who are doing it - they're all buying 7950s.
Personally I've chosen not to go that route, I've sold off all my GPU and will stick with btc. After 2 years of massive electric bills, constantly fixing issues and dealing with cooling costs and the incessant noise of a gpu farm - I'm done. I'm glad I did it, but am very relieved that asics are available (with more offerings in the works!) and after switching over I haven't lost any hash-rate... but I have lost the fan noise, annoyance of keeping so many machines running and headaches associated.
Really the only way to get into bitcoin mining right now is to throw lots of money at it. If you really wanted to spend between $50000 and $200000 I'd be happy to advised you on the path to getting it going and actually making money off it.