You can use anything on a mech that you would use on an ego or vv/vw mod or whatever you are currently using. With a mechanical mod, you are limited as far as what voltage you want to use since the voltage of the mech is the voltage of the battery (which is around 3.5-4.2 volts depending on where your battery is in power left). To get around this, mechanical mod users put low resistance atomizers/clearomizer/cartomizers on top. This will give you more power, despite the limits of the voltage you are vaping at.
Basically, yes you can use a mechanical mod and get great performance out of it using any stock clearos, etc... It is best to use a low resistance atomizer (around1.5-2.0 ohms) to get a good vape. Some stupid idiot jerkfaces have been hyping the 'subohm' craze. Basically it is exactly what it sounds: using an RBA/RDA that has a resistance less than 1 ohm. What, you say? Sounds stupid and dangerous? You might melt your face off? Psh, nah bro, it is INTENSE!
You would not be just throwing money away by picking up a mechanical to use something like a Protank with. I have a few mechanical mods and I enjoy them. Sometimes, I use Protanks with them and sometimes, I throw some of my RBAs on them. That said, most of my builds have been over 1.5 ohms, which is pretty much the lowest resistance you can find clearos at