Check on Amazon.ca. There are usually numerous UTH available. Although I am unsure as to why you take issue with the adhesive - you will most likely never have to switch it up as the weaker wattage UTH aren't any good for a larger tank should you choose to upsize in the future. I've only ever used ExoTerra brand UTH. But if you want a pad without adhesive, here are some:

https://www.amazon.ca/s/ref=nb_sb_ss...=2KAY3WXYTXU74

More importantly, you should also invest in a thermostat and thermometer. For the former, the ReptiTemp 500 is a great product, but I've found that the JumpStart is a far superior product:

https://www.amazon.ca/gp/product/B00...?ie=UTF8&psc=1