Finnex makes a 500w titanium heater that works off a digital touch controller, so you can easily change the temp without reaching in the tank or taking the heater out of the water..the controller also has a nice, bright, LED temperature readout which is convenient sometimes...
The digital temp controller may be a bit of a novelty (I admit that mine barely gets used), but it does make it quick and and easy if I do have to adjust the temp...I can easily change it and easily see what it has been changed too..For me personally, I went with this one because I have my heater hidden pretty well in a custom-made 3D background, so I just like knowing that if I DID have to adjust the temp, I wouldn't have to worry about reaching in the tank and most likely having to move it to adjust it, or having to take off my 7-foot canopy and glass tops, just to reach in and change the temperature 3 degrees, but I guess it depends mostly on your setup...just something to consider in advance...
I have one 500w heater (Finnex HMX 500s) in my 7 foot 200g keeping the tank between 77-78 perfectly...hope it's ok to post a link here - currently about $55 on Amazon for the digital 500w but they have smaller ones too...