Your fan idea should be fine. I opted for USB fans. I bought two twin 80mm fans. Total power usage is really low around 3w.
There is a thread on Homebrew talk that has many common freezers fully spec'd out.
I have an 8.1 danby, and a 10# talk will fit with my 2x6 collar, but only if I get the shorter tank. I can't always guarantee that I will get a short tank when I exchange, so I opted for it to be on the floor for now. The difference in size for the short and tall is only a few inches, but it's enough to keep the lid from shutting. Soon it will be outside the collar, I don't need it taking up keg space.