Both of my grandfathers landed in France immediately after D-Day. One served with a mechanized cavalry unit and was positioned offshore during the invasion but had to wait a few days to land. He was at the northern end of the 'Bulge' and helped repel the Germans from his sector. He was in Czechlaslovakia at the end of the war. The other, a combat engineer lieutenant, arrived in Normandy after the beachhead had been established, July or August I think, and ran a supply transfer point before moving inland to Antwerp and eventually into Germany.
Anyhow, I've always been primarily interested in the campaign in Western Europe. I was able to find several months of original after-action reports from the cavalry unit, hosted online at Carlisle Barracks, Pennsylvania, and even found my grandfather's name reported within! If you are willing to share your grandfathers' units I wouldn't mind trying to help you find information.