The easiest way to allow Internet access (not necessarily the most secure) would be to network both systems; if not possible from your router, a small (4 port) hub can be had for well under usd50.00. Once the systems see each other, choose one to be your “primary” PC, install the Aircard and configure Internet Connection Sharing (ICS). This will allow both systems to use the card to access the Internet. You can access ICS from “add and remove programs” control panel (Windows components).
Because you were asking for a Wireless ISP Router, I believe this would be more in the lines of what you would like:
If you are looking for a router that you can connect a Wireless PC Card you would be referring to routers such as the Junxion Box, make sure to check if your Wireless Carrier and wireless card are supported prior to purchase.
With devices such as these you would create a local wireless network and the PC card would provide the WAN access.
Also check out Digi box from and the Linksys Wireless-G Router for Sprint Mobile Broadband WRT54G3G – wireless router
I hope this helps.
Victor Cavendish Góes