KX125 For Hare Scrambles

I'm looking at building a hybrid bike using a KX125 chassis with a KDX 200 motor. It will be built to run hare scrambles as well as some occasional playing on the MX tracks.

I'm wanting to know what the best choice of a KX would be for what I am doing. Is there much difference in the suspension and chassis between the various model years and if so, which model would work the best? For the application, is it worth spending another grand to get a 2001 instead of a '98 if both are in similar condition?

Any input would be greatly appreciated!

I have heard about the Dynoport pipe but the I've heard they it is being discontinued and they only have a couple left.

I do need to talk to the Doc but he's not due back until the 18th.

Thanks.