There is alot of nice 4-strokes coming out.. Can-am's 450 looks nice, polaris outlaw 525 and the 450 (uses straight axle) are the newest models. LTR450, YFZ450 are very nice too. Go to your dealers and sit on them and see wich one fits you the best and tickles your fancy. They're all pretty nice if you ask me. But for track you might want to stay clear of the independet rear suspension. They tend to have alot of roll in the corners.