The allied D-day book (Turning Tide) that is coming out in January is by far your best bet, although a bit pricey (Also available now as part of a very pricey box set with the german book). If you want something cheaper and more tank focused, 2nd and 3rd Armored Divisions are covered in the Cobra book. Bloody Omaha has some mech infantry lists too
IIRC but is going to be combined with the cobra book and others in the forthcoming d-day book.
Personally I'm waiting for the battle of the bulge book before I start a US armoured force
...oh and of course Fortress Europe has the basic lists for flexible usage for all types of forces (infantry, mech, armoured, recon, etc) for US, German, Brits and Soviet.