what guage wire to use?

Hi again everyone, I am getting real close with the Bridgeport cnc
conversion, and have yet another question. I am using 750oz motors
from TMG and gecko drives along with a power supply from Bill
Griffin. The motors came with 6wire molex connectors on them, with
the .093 terminals. I went to radio shack to purchase the mating
connectors, and I see that the maximum size wire that can be put in
them is 18 guage. That seems a little thin to me, I will be putting
about 5 amps through the wire, will 18 guage be OK?
Thanks; John