Ok you are opening a huge can of worms here, so lets break it down a bit.
Firstly, are you after a stock or a jump bike? Two different things?
Secondly, what kind of things did you look at on ebay? What brands, specs, prices?
Thirdly, anyone can give you an opinion on what they think is best from what they have ridden. You may need to spend some time thinking about the type of riding you want to do and what bike you think will suit then people can make some tailored suggestions around that.
Hope that helps,
Brett