Optiplex 360 NIC upgrade for Win 7

With the ending of XP support in April, I have about 40 Optiplex 360s that I want to upgrade to Win 7.

I have run the MS Upgrade Adviser, and the only thing that looks suspect is the Broadcom NIC card. That being the case, I am thinking it would be cheaper to upgrade the NIC and O/S than replacing all the units.

Would anyone on here have a suggestion as to a replacement NIC card for this 360 ? This seems to be a standard desktop, but I believe it takes 1/2 height cards?

              Any help would be appreciated...