keep in mind that the stock transmission x-member and hoop are an integral part of the "frame" and because the t-bars anchor there it is critical to retain the structure and if modified to substantially beef it up.
i only say T5 because the road has been traveled before and the parts are there. they're rated about the same torque wise. but you're in a light car and you'll have limited tire width-- unless you mini tub out back.
there's somebody on here running an ax15... i forget who but it's seemed to hold up thus far