355 Challenge, what are the differences? is there a register

[jazzybee]

I am toying(at the moment, no more than that) with the thought of a 355 - I nearly bought a challenge about 10 years ago but just because it looked a good deal. Now, I want to understand the differences in more detail- is there a different suspension setup, the one I saw long ago appeared to be sitting lower. Are there different models and options? was there/what was the 'comfort' pack? These are the sorts of questions I had - is there a dedicated site or register to the 110 or so cars built?

Thanks