Like HiSpeed said, 003RS will do just fine. Personally I would not go off size on tires unless I absolutely have no other option. You can pretty much shoe horn any size tire on your 4" rim and they will “fit fine”, at an expense of severely altering the intended tire profile.
If you are doing the forks, I would suggest finding a shop that actually knows what they are doing to do them for you. It is not really that expensive.
Enjoy!