I almost made the same mistake. The GP 10 reflector tape is ONLY for the targets on the vertical poles. Use the KOP reflector tape on your pole targets. 2" squares will probably work fine.
THe GP 10 is NOT for the floor marking tape.
from the rules
"TRACKING LINES are marked on the carpet with 2-inch wide grey gaffers tape."
and that is relatively cheap, something like this
http://www.goodbuyguys.com/catalog/p...products_id/57
You could probably go to home depot and get a roll of 3M electricians bundling tape. It looks like duct tape but it isn't and is similiar to gaffers tape.