Your expecting 1 or 2 clutches? A cooler incubator I think is your best bet. You can't really screw up making it. The thermostat does all the work. You just line the top edge with the 3" flexwatt, put in your medium, if you choose to use one, then seal the top with press and seal, voila! Egg incubator!
If you would still like to buy one, I think of Nature's Spirit. They make a nice one out of PVC, and has a helix... but I really can't think of any smaller sized ones off the top of my head.... >.<
Maybe your breeder friend has a some extra room?