if you already bought rotors slotted , and they are stock size you will be stuck with stock calipers.
Most of all the Caliper upgrades require larger rotors thats why they come in a kit all together.
But you may hav clearance issues with your fadtory rims if you get larger rotors & big calipers.
I bought a kit from Baer , both fronts about $1500 for parts & shiping. Well my stock wheels were to small, sucked big time! So one day if I get bigger rims I'll put'em to use.
Something to look for when you replace calipers is a NEW one, not one rebuilt by some guy whos in prison making like $1 a day
Dont forget to buy one of those kits with the new boots and bolts and release clips
Napa is a good place for parts, better than the outpost you were speaking of