Mountain Biking - So i got a P Street?

ok so got a p street from a guy on craigs list for a great price! i took it out in the woods once so far tottally stock with slick tires on it i quickly found out i couldnt hang with the guys on the full suspension santa cruz's! So i bought a pair of Panaracer fire tires and threw those bad boys on there. Now heres what im wondering how hard is it going to be to convert thist bad boy to something that might have o lets say 9 gears? do theymake bolt on derailer hangers? or a verson that i could weld on very easily?
Iv already came to the conclusion ill have to lace a new rear hub into my rim no big deal... allso i was wondering if there is a diference in the drop out width between (ie a bike with gears or a single speed freewheel bike)? i guess thats my main concern, if i can get a (im only assuming) wider rear hub in there?

Im not to knowledgable in the mountaain bike world but i am by no means a moron.....im just coming from riding 20+ years of bmx and a little bit of fixer gear riding. Basicly im looking to make up an indestructable free ride bike that will put up with what i throw at it. wheight isnt really and issue. lets hear it boys and girls throw them ideas at me !

I've never tried BMX stuff, but I guess those bikes are probably pretty heavy duty (and plain heavy). I don't know what riding you like, but unless it's pure down-hill, you will go a whole lot faster on a lighter bike than a heavier one.

a p. street was definetely not the best choice. p.street is mainly designed to be an oversized bmx. the ropout should be the same size, 135mm. it's super super strong, but was designed to only run 24" wheels, so you maybe screwed there. you may be better off with a p.2 or p.3. The derailleur hangers that work with the current generation p. cromo are an attachment that slot into the rear dropouts, and you bolt them down with the axle.

I've never tried BMX stuff, but I guess those bikes are probably pretty heavy duty (and plain heavy). I don't know what riding you like, but unless it's pure down-hill, you will go a whole lot faster on a lighter bike than a heavier one.

You also go faster with a lighter bike downhilling. They also aren't to over built, I think they're around 31lbs, they're cromoly so they don't need to be overbuilt to much.

ya i pretty much know lighter is faster...im just looking for another toy really, and i dont feel like spending the 1700 on p3 when im sure i can convert the p street i got for way cheeper( i traded it for an old snowboard) im pretty sure i can have a bike that weighs a bit more if it cost me 1300 dollars less no big deal to me im a strong guy.. so any ways any god sugestions on what kind of derailer? and what abbout that e thirteen stuff iv been seeing around? good bad ? waste? to heavy?

again, as i was saying, the p.street isn't designed to run gears, nor is it designed to run a chainguide. i'm not sure if it even has the iscg mounts.