This would be the wrong place to discuss a full tilt Banshee,
but if it weren't, My God, are those things a blast! Same thing there though, you wanna play, your gonna pay....
If I were going to get started in some lake racing with a clean slate, I'd probably be taking a hard look at a Polaris 600 twin. Quick out of the box, big enough to scare you if you do something stupid (to keep things interesting), and responsive to inexpensive mods- just like the Banshee, only not as much grit in your teeth after playing for an afternoon!
If you're a big guy, say 225+, or a certified adrenaline junkie, again starting with a clean slate, you might want to look around for a Storm w/Xtra10. They can be bought right with careful shopping. Haven't decided if going to the 800XCR is worth the money on a lake. The extra cc's and horsepower would be more forgiving of a rider's extra weight. They are sturdy. It WILL take some work to get it sorted out, and God help you if you scatter it in the process. The end product is worth it though. They are definitely impressive on the ice when properly set up, to watch, OR ride.
My 2c.
AL