Get the freezer. GE has a chest freezer that will fit two carboys in. I bought it on sale for $158.
As for the temp control take a look at Control Products two stage controller. It has two relays one. You can use one for cooling and one for heating. You do have to do some wiring to configure it but its not hard if you have the head for it.
I am currently conditioning 108 bottles of beer in my freezer using my controller to keep temp at 70.
Here are some pics of the controller