you've gotten very good advice from mark and dave--and uncharacteristically, for the forums, both acknowledge there are multiple ways that will work: that's a point all too often overlooked when people assume something works for them therefore MUST be the only right way, and others--and their ways--be damned!
what i like about racks (I incubate on shelves in my snake room) is there's nothing electrical to malfunction and cook the eggs. I keep the room at 80; the eggs are at 80; barring an extended power outage, which here in west-central florida could spike temps to 100 in my room, it's a nice stable environment. And if that did happen, i could always move the eggs to a friend's house where the a/c was still working. The bigger worry would be the snakes themselves.
With eggs, I've heard a lot of horror stories about people whose incubators malfunctioned & cooked their season, in one instance tens of thousands of dollars of python eggs. So if you do rely on an incubator, be sure it's working right and eliminate as many as possible of the things that could go wrong!
peace
terry dunham
albino tricolors
st pete florida