What kind of hood / lighting do you have??? my light used to heat my 50G up 2 - 3 degrees easy.
Any good heater will do you, I personally like rena
I have a pair of Rena Cal Excel 150W Heater 701D (Aq. Pharm.) in my 2 50G and they work good. Temp don't change to much on me. I still don't use the temp thing on the heater but go by the thermometers I got in there.
One Fish, Two Fish, Red Fish, Blue Fish