i've read and heard so many things on heaters, what brand and wattage would you recommend for a 65 gallon?

If the heater is going in the tank with your Oscars then I would suggest getting one that is very robust because O's have been known to break heaters. Follow the link below and see ones that I recommend

http://www.charterhouse-aquatics.co.uk...w-heater-p-1988.html

sorry, i have not used any heater in my place....
couldn't give any inputs. i only suggest you get
the one that has auto-off switch when out of water.

i was told by my lfs that its 1 watt to 1 litre of water so if you gor a 200 litre tank then a 200 watt heater will be enough.dont know how true that is but thats what ive been told

Just testing to see if my text appears

EDIT

try posting again

i highly reccomend the rena smart heater as they are metal not glass and are what they say on the tin UNBREAKABLE.....they have very accurite thermostats that can be set to within half a degree they are relatively cheap to buy and i would reccomend you get the 300 w as if you increase your tank size later you got a great heater that can cope with a very large tank......i am using them in a 10 gallon hospital tank and a 165 gal display tank and they perform impecably in both...........over the 25 + years i have kept fish and used heaters of all types and makes ans watt.these are by far the best