If you're clubs race Trucks..then get a Truck
SC is not going anywhere any time soon. In the UK and Europe it might not be massive but basically every club in the US runs SC and will run SC for the foreseeable future.
I like SC and will probably add one to my collection eventually.
As a note... most SC cars are a convert or variation of a buggy...so with a small amount of parts swapping you can easily convert a SC into a buggy or vica versa...in fact a few kits have come as both.
J