Better to match your heaters, whatever they may be. Also good to get 2 heaters instead of 1 in case one malfuncions (in the off position, nothing is going to save you if it gets stuck in the ON position and you don't notice).
I have 2 150w heaters in my sump for my 75G, both Jagers, but I really really need to replace them. They are over a year old and the latest info making its rounds in the hobby is "Heaters only last 12 months in saltwater tanks and must be replaced whether they appear to need it or not, they start to leak voltage into the tank in high amounts after a years use". There was a speaker at IMAC in LA last month that talked all about and showed conclusively how true that statement is. Everyone leaving after the speach was over was like "Wow... I am buying a new heater on my way home after hearing that guy". I bet 1000 new heaters were sold around LA just because of that one speaker at the Expo. lol.
IMO there really is no "golden heater" that stands out above the rest. There are "junk" heaters, but if you pay $5-$10 for a heater you should expect that. The main brands, Hydor, Jager, Stealth, etc, all seem about the same from my experience, none great, but none terrible either. Just replace them every 12-18 months and you should be good.
