Tire Reccomendation

I have a 99 s-10 blazer 2 door 4X4. I am in need of new tires and want to change the look, looking for something more aggressive, and possibly bigger. The placard on the inside of the driver's door reccommends P205/75 R15. How much bigger could I go, and what would I need to do to adjust for bigger tires.

Also, any ideas of how I could beef up my suspension without spending a fortune?

Thanks!

there are lots of things to do
wind up the torsion bars and get your leafs arched up a bit thats a cheep way of lifting but it will cost a an alignment and like 80buvk at the spring shop
and for tires205 seems small on that truck i have 235 75 and thats the factory size. i think u should look into how high u would have to go in order to put 31x10.5 on cause i don't think it takes much
and Michlen is the only tire that i would use