I use S-05 and S-04 quite often as I just enjoy a good clean yeast. I really should start branching out, but it's hard to commit to experimenting when you only get to brew so often.
Do you have a stick on temp strip for your fermenter? Before you buy your pad, I'd check to see what your actual fermentation temp is. If your ambient air is around 65, it's entirely possible you're fermenting at 70+, in which case you don't need a pad, and it's possible that you're just having the same issues a lot of people do with extract kits. If you're actual temp is around 65, then yeah, a belt or pad, or I use a heating blanket in my ferm chamber(ghetto, I know, but it works!)
As for temps, a lot of ale yeasts seem to have a low end temp of around 63-65. S-05 is a good yeast, I think, (some will tell you otherwise, but give it a whirl for yourself) and if you can maintain a temp of about 66-68, I think you'll be happy.
Good luck with the next batch, and remember, patience, patience, patience!