- Use 64 bit if possible. All virtual memory space is directly addressable even you add more memory later on. For 32 bit system, directly addressable memory is 4G. But internal system will need 2G.
- memory: the more the better within you budget (but under 64 bit system)
- NIC: wired is always has better performance than wireless counterpart. Wired interface comes with motherboard. Why expect dual purpose card? I don' know if such thing exist.
I can not give suggestion about video vard, since I am not game player.