Hello,
I already have a WISP using Wingate as my main gateway, and it works fine, though wingate doesn't have bandwidth throttling.
For primitive bandwidth throttling you can use Bandwidth Controller:
http://www.bandwidthcontroller.com
Bandwidth Controller only works on Windows 2000 and XP. Also, it currently supports only 50 shaping rules.
If you are going to use Wingate as your ISP's main gateway be aware of the following shortcomings:
-It doesn't route public IP addresses or address ranges.
-No bandwidth control
-no UPnP
-Many people have problems with the NAT after version 5.07 because Qbik changed the architecture after it split with Deerfield