They're like saw blades; Some are optimized for certain materials, material removal speed, roughing or finishing, etc., but you should probably just get some general purpose or roughing ones if you're just doing a deburr where it won't be seen.
There’s also a really good selection at your local Fastenal. That’s where I bought mine. Chucked in a Harbor Freight electric die grinder. It has adjustable speeds for different materials. Used mine to clearance the Toyota knuckle balls when I upgraded to RCV’s.
The burrs fastenal stocks are mostly the expensive ones. If you know what your looking for, usetheir website to find the part number. Then have them order. I find most of the ones i use are about 12 bucks a piece through them.
If doing steel keep a small rare earth magnet for helping get them out of your eyes. Unless you my BIL an do aluminium then have a eye doctor on speed dial.
I just got a set of these. Cheap. I've only used one, but it did a fantastic job opening up a slot I had plasma'd a little too small in a bracket. Worked as well as any burr I've ever used. Will it work as long? Maybe, maybe not. Also, it's not a 1/4" shank, probably 6mm, but my collet still cinched down on it.