There is a cross reference as to which parts fit. You should be able to find it on here some where. Also many on here also purchase items from Europe, where Carson offers more options. If you look up Hobbthek on google, you should find their site, it is both in German and English.
It all depends on what you are looking for, the chassis it self is not bad at all. You can always modify here and there, but if you don't beat it to death it should last you a long time. I have had my FG Marder now for almost 8 years and it is still going strong, with minimal parts breakage.
Thanks for the replies. I'm not looking to modify this MT much, as I already have a modified Baja, I'm just looking for something to bash around with, for the wife and kids. Here are a couple of pics. the guy says it has about 1 hour of run time, almost new.