I know this has been talked about before, but why not talk about again. I'm looking to build a bike primarily for GP/6hr/24hr style racing. I'm not looking to spend a ton, but want to do it right and make sure the bike is as solid as it can be. The biggest things I'm looking for are parts availability and reliability. I was looking for input on what might be the pros/cons of going with an early 2000's steel frame or a 05+ aluminum fame YZ.