South Valley is good, or if you're looking for a shop close to home try Hunter Machine. Also, I'd just get the machine work done, then buy the parts through Summit Racing and assemble the engine yourself if you want to save some bucks.
You'll need a new crank and rods to build a stroker, so that's going to add to the cost substantially.
x2 on assembling it yourself. Have the shop do the bore/hone, assembly of pistons and rods (they should have a rod oven, VERY USEFUL!), and the cam bearing install. Everything else you can do yourself.
Also, BCGPER posted you a link to some stroker parts, and along that line, there are a lot of cheapish stroker kits for 350's out there... Powerhouse, at
www.enginekits.com, has some: but watch out for off-brand bearings and whatnot. PAW also sells strokers, but usually w/good bearings/gaskets.
Summit sells rebuild kits with excellent parts, and not a lot of money.
And finally, Pro Machine did a Jeep 360 for me in '97 and I remember that it cost $8/hole for the bore job, and I want to say about $400 out the door for a bore/hone, wristpins, cam bearings, and a good cleaning after they got done so I could just get on the assembly in the middle of winter.
Anyway.