I second the suggestions to buy ready-made 12-2 cords and replace the ends. The existing ends are cheap, even for 220 V.
Also for the suggestion to drop from the ceiling instead of running along the floor. Use a hanging strain relief or, in my case, a retractable cord reel ($$, but worth it) so the cords remain handy, but out of the way when used for cars. Don't keep all the extra cord on a reel that's dedicated, e.g. for your table saw. Cut it to only the length you will need and avoid the extra voltage drop of the long cord.
Don't hard-wire the fixed end of your cord -- use a plug and receptacle; otherwise your cord picks up a bunch of additional code restrictions.