umm i dont think new studs will help with clearance. if u like the wheels and want to keep them sitting in the same position of the guard ie. not poking more, you may want to consider new suspension with a tighter coiled spring, as it will give you more inner clearance room.
with spacers you dont want to use a slip on, and hubcentric spacers are hard to find for 4x100, and are gonna give u a fair bit of poke.