I think I would go to a different builder. Network card technologies are nothing new - and neither is 64-bit. Nor is it very high-tech. Because of that, almost any brand will work, but I prefer to avoid buying anything generic or off-brand and stick with the major players like Linksys/Cisco, Netgear, Belkin, D-Link, Buffalo, ASUS, or SMC. And while USB interfaces are generally very good too, they rely on USB which has been plagued with problems since the beginning. Fortunately, the recently released USB 3.0 standard seems to be much more stable, but then stability was a promise from the beginning, and again with 2.0, but never realized. But finding USB 3.0 devices is still hard.
USB devices are also cheaper, but most don't have as good a range as cards with external antennas. That said, I've used the
Netgear WNDA3100 on several 64-bit Win7 systems with no problems in terms of connection or range.
Newegg has well over 100 USB and card adapters to choose from. I would pick one that supports Wireless N (802.11n) even if your WAP does not. This way, you will ensure you have a newer adapter. Read the specs and choose one that also supports 11b and 11g (if you need that) and they should also indicate which operating system, including 64-bit, they support. If they say Vista support, it should work with Win7.
If your WAP (wireless access point) does not support 11n, I would recommend upgrading it as soon as budgets allow.
Note that one problem that often affects all PC wireless adapters, card or USB, is that PCs are often located on the floor, and the with cards, even closer to the floor. And being in the back of the computer, surrounded by all sorts of data and power cables - not, by any means, the ideal location for the best radio (wireless) reception. So an adapter that allows you to relocate the antenna may help.
That said, Ethernet is still the best bet, in terms of stability, speed, and most importantly, security.