I don't use anything other than Ebo-Jagers on my tanks, they are some of the best heaters that money can buy, and the most consistent temperaturewise with very few incidences of malfunction. I also would recommend a 250w for your size tank.
There are 2 places that I highly recommend for online aquarium shopping :
is a huge favorite amongst most aquarists who shop for their supplies on line, as is
where you place a bid for your products and I have found can be even more cost-effective than Big Al's at times. I was able to get heaters for all of my tanks for just pennies from Kensfish, who is a seller on AquaBid that I personally have dealt with and have had excellent service with.