My experience with two different 160GB IDE drives on the A4000 is that HDToolBox only sees something like 128GB of the drive. So it might be possible to use it, but you might not see the full capacity.
Also, for wireless, AFAIK you can only do WEP encryption. If security on your network is a concern, you will probably want to stay wired. Otherwise you can use an open network with MAC filtering* or WEP encryption.
* Again, from a security stance, MAC filtering can be spoofed (that's partly how TJX happened) and WEP encryption can be broken within minutes.