This sucks, sorry to hear of your troubles.
20 miles with low oil and pressure lights likely killed the engine. It may have already been too late, depending on the original problem.
I blew up a car once within about a mile after the oil light came on. I was about 2 miles from home :(
If you ever see that light, PULL OVER IMMEDIATELY! It isn't a "warning" light per se. It warns you to get teady to walk,unless you pull over n.o.w.
Good luck with your repair/replacement. If you need us to search out parts, etc, just shout.