I've heard a good hole saw is a slow drill press. I have yet to try it but I sure have killed a few at speed.
The local electrical supply house is where I get my hole saws. most carry Lennox but the greenly, Ideal, Klein, brands are all pretty much the same. Some have hardened steel teeth welded on and they last the longest. Keep them cool and go to town!
Always buy a bi-metal hole saw hopefully with variable pitch teeth. Lenox and starrett are all good. run them slow
I use rigid and Lennox ,Dont ever use a drill ,Just destroy's them ,Set your drill press on the lowest speed and use oil and your good to go ........I prefer rigid but I hate Home Depot .Ill shop there but only when I have to.