17x8 in the front with a 4.5” backspace won’t let you run more than a 225 wide tire at the most, which will be stretched on an 8” rim. For 17x8’s in the front you want at least 5” of backspace so you can run a decently wide tire. Otherwise run a 17x7.
If you’re running spacers in the back to go from 5x4” to 5x4.5” then 4.5” of backspace on a 17x8 might not be enough backspace in the rear either. But it will depend on what axle you’ve got and what spacers you’re running.
yeah, bolt on adapters will be at least 3/4" thick (1" thick if you want the original wheelstuds to not stick past the adapters, you need a pocket in the wheel to run 3/4" thick ones). that will effectively add 1.5-2" to the rear axle width.