Yes, you can search around for a temp. switch that has the range you want. You may also need a bushing because sometimes the thread size of the switch you find won't match the opening you want to use. If that's the case be careful - the tip of the switch needs to be fully immersed in the coolant; many bushings are so big that by the time you get the switch screwed in, the sensor's not fully inside the manifold or radiator and this will affect it's accuracy. You want an 'off' temperature that's at least 5F-10F above your t'stat temp, or the fan won't cycle on/off -- once it comes on it'll stay on. So, if you're running a 180F t'stat, you need a switch that cycles off at least 185F-190F. They usually have 15F-20F range on them, so switches like that will turn the fan on somewhere in the 200F-210F range. I use a 210F on/195F off switch with a 192F t'stat. I measured actual temps of the devices by placing them in a pan of coolant (40/60 mix - more water) on the stove with a calibrated thermometer. The reason it cycles ok on mine is because my 192F t'stat actually begins opening at 189F; my switch doesn't actually re-open (cutting the fan off) until about 197F. So, cruising down the road the fans aren't on. In the winter the fans rarely come on. In the summer it will cycle between about 210F and 197F. Be sure you install your switch in the proper location - I'd want it near the t'stat or near where the upper radiator hose enters the radiator. And you'll still need a relay too; relays if it's a dual fan set up.
