22 gauge is the size wire that I've seen most people state they use. I bought 2 spools of 100' 22 gauge wire to wire my cabinet with. It sells pretty cheap at the local Radio Shack, so buying the extra is not that big of a concern.
If you goto the radio shack website, search for part number 910-1775. The insulated .187 female disconnects are on sale right now. The local stores had them in packs of 10, and would have cost me twice as much to buy them that way for the quantity that I needed.
Daniel