One iLok should be plenty, unless you're running both computers at the same time.

Thanks for that, I guess I'd need two, as the computers wont be running at the same time but are in different locations.

iLok is made for that situation, leemac.  Your authorization for the plugin(s) is held on the iLok, which is just like a usb thumb drive.  You unplug it and plug it into your other computer, which already has the software installed.  The iLok allows it to run instead of running in demo mode.  Same thing when you upgrade a computer - you don't have to go through the hassle of authorizing every plug in.
 
I've had an iLok for years, running it w/o problems.  They had a glitch the last time there was a (free) upgrade and they rejiggered the web site.  They got it fixed.  Otherwise, it is pretty much set and forget.
 
If you are doing daily professional work such a problem would be problematical, as well if all your plug-ins are iLok.  So I'm glad for Cakewalk and other kinds of authorizations - I was able to work around the lack of iLok.  Still, I've had no more problems w/ iLok than other kinds of authorization.  Even w/ Cakewalk, there was a problem not w/ SONAR but getting my reg number for the bundled Dimension Pro to be recognized.
 
@

Thanks for the info and putting the time into replying, its helped me a lot.