Cutting rust from a truck frame

Fellow Dremelites,

I need to cut some rust from a 2nd gen 4runner frame in a really tight space. What bits would you recommend for this job? Thinking of the quick change metal cut off wheels, and some larger carbide bits to grind away some of the cuts for welding. I will also need to grind the welds down as well. I'd use a large grinder but I think this calls for a special tool like the Dremel.

Thanks!