here is what i think with the heaters i have used
aqua one, cheap and so so, you get for what you paid for
Fluvaltronic, i would never use one again, had them in 3 of my tanks and they just failed one by one (two wont heat and one boiled my fish)
jager, a awesome heater, never had any problems, i have them in most my tanks now...only thing is that the 300watt one is SUPER long! and you need alot of room for one
JBL (dont think you can get them here?) another great unit, you can get a 300watt heater that is very small and powerful