I would have to partially disagree. Certainly the workstations can use 1GB, but I would use more memory on the server machine. While GB connectivity probably doesn't speed up the connection, it will make large files import faster.
XP Home will definitely work fine for a peer to peer workgroup, if starting fresh, I would recommend Pro as it will give you much greater flexibility if you convert to a server/client domain setup where Home won't even connect.
If the bottleneck is due to using wireless, then I would assume it is due to bandwidth, which is faster on wired, therefore wouldn't 350Mbs be faster than 100Mbs?
