I'm in progress on the crossmember. Today I drilled the 1" holes for the side frame bolts. Despite all of the excellent suggestions, I went ahead and purchased a bi-metal hole saw (1" as the directions say), and went to town. I already had the 4 holes in the bottom frame, so I only had to do the 6 on the sides. The hardest part was making sure I center punched the center of the hole.
Once I was comfortable that I had a centered punch, I removed the frame supports, and drilled away. As most of you probably know, the hole saws come with a pilot drill in the center, so I improved on my punch by drilling a small hole (3/32nds maybe). This gave me a very good pilot for the pilot!
Actually cutting the hole was not really hard. I let the hole saw do the work and just concentrated on keeping it straight. The first one was not quite straight, but the remaining 5 went very well.
After drilling the 3 for a side, I supported the crossmember with a jack, removed the crossmember bolts and bolted the frame spacers to the frame support. To check my fitment, I then slid the frame support (with the spacers attached) into the freshly drilled holes. I was able to thread in the bottom bolts, thus I felt confident that the holes were properly aligned. There was a small amount of slop allowed in the frame holes as I did not tighten the spacers fully tight to the frame support. Everything seemed to line up ok, so I'll just have to hope they line up the same way after welding the spacers in place.
Once they are welded in place, I'll do like Wayne suggests and drill the hole on the other side of the frame.