so that's X2-3 pieces in the .75 inches and less range - assumign you'll be climbing harder and harder (read longer and longer) crap, you'll need more gear - especially if you just give in and go over to the dark-side of aiding
having at least 2 of the following makes it such that you can usually make a fine rack when climbing w/ someone else who has some shit:
blue, green, yellow, red aliens (.5, .4, .3 and .2 inch pieces - i like having 2 of each alien, than having 1 each of the same size tcus)
fun, hard routes invariably lead to wider cracks though, so eventually having 2 in the .5 to 3" range will be necessary