I'm going to be setting up 2 150 gals with a 100 gal sump, and possibly a 50 gal tank as well. What type of heating should I get to heat these tanks? They will all be running off of the one sump so the heater(s) will be placed in the sump.
If you're planning to go with a temperature controller, most average quality heaters would do. You'll want something durable. So the titanium you linked to would be great, I also like the Stealth heaters. You'll want to go with multiple instead of one, in the event that one fails.
The wattage that you'll need will greatly depend on the ambient temperature in the room. One of my systems is 400 gallons, with a sump in my basement. Since the sump lays on the basement floor, it tends to keep the water on the cool side. I run around 1000 watts worth of heating.
On another system that I have, around 300 gallons, I run around 550 watts worth of heaters and that's fine because the ambient temp is higher.
Either way, a temp controller is an excellent idea. I would invest in a good one such as a Ranco or the Ranco rebadged as AquaLogic.
I agree with Law. I'll be useing two 350 watt pro heats on my 350g with 100g sump. If one fails it's nice to have a backup. I keep the ambient temp in my home at 63 degrees in the winter but the tank and sump will be well insulated. During the summer I allow the temp to come up to 80 degrees inside the house and the heaters on my other tanks don't even come on.