EZAccessory.com offers up some pretty good ones; I've bought bolt-on adapters from them several times. For a 1" spacer you will have to cut your studs down a little, unless your wheels have pockets in the flange between the lug holes where the excess stud can go. Measure carefully before depending on this.
Proper installation is so ridiculously important...it can be tough to torque them properly; have a helper stand on the brakes like their life depends on it. If the rotor or drum turns at all while you're torquing, the reading is false. You'll also want to re-torque just like you should with aluminum wheels; after 25 miles or so pop your wheels off and re-torque the adapters. I'm paranoid and tend to check them again and again until I'm satisfied they aren't coming loose. No need for any disasters...
Richard