xD Yup, I have a 25w hydor theo heater... It's badass, if I do say so myself ^.^ In the 5g it's sitting in now, I have it set on 80, and over night it's gone up to 82. I'm assuming it's not going to go up anymore, though, since that's how it went with my 1.5g, but I'm still gonna keep an eye on it just in case. ANYWAY! Here's the site I got it off of. It was the cheapest I could find with shipping included at the time:
You might still want to browse around online on the off-chance you can find one that's a bit cheaper, but this was the best deal on this heater I found, and it works great ^.^ Just keep an eye on the shipping fees. I found that some seemed like they were a better price, but it turns out the shipping pushed it to where I was better off looking elsewhere.