Yes, not all rap is going to fit the fast rap bill, and Paul's Boutique is certainly not one of them, though it might be the best rap album ever. Just like I wouldn't recommend PE's Nation of Millions for "fast rap"...but I would recommend the hell out of it in general.
Man, PB before...
Yes, Outkast is a solid band doing some interesting stuff. B.O.B. off of the Grammy-winning Stankonia is exactly the sort of fast rap you are looking for. It has a hard, thumping drumbeat to it as well for a "hard" edge.
Rap/metal mix - one of my favorite rap albums period fits this...