It's really a matter of preference, but I know with quick disconnects you can use a very wide variety of gauges and be ok. I like a little bit of a thicker wire for durability and wire management (thicker wire bends and holds its shape better). In my cabinet I used quick disconnects with stranded wire, but if I were to do it over I'd probably use a solid core wire as it's even easier to bend and work with.
You'll be fine as long as you don't use that really skimpy super thin stuff. Don't fret too much, you're not sending a lot of power through these things. Just use something that you feel that you can work well with.