Mk4 with Chev LS and what automatic trans?

[tmatts]

I'm making plans to purchase a MK4 and I have a few questions that I haven't been able to figure out by searching the web site. The plan is to use an LS3 Chev and I'd like to run a 6 speed automatic. Which automatic options fit in the MK4 chassis? I'm also wondering if the front suspension of the Challenge car is able to be installed and used with the MK4 chassis? Can an IRS be built into a Challenge car? My other thought is to buy a Challenge car but reduce the full cage down to just the rear section. I would like to autocross and street drive the car. Also I'm in Canada if that matters.

Thanks.

Matt