Yes, the RFX9400 or RFX9600. I've seen many of the RFX9600's on ebay lately. The RFX9400 is more scarce these days. The manuals for both are on this site.

The RFX9400 is capable of doing 'Standalone' such that it creates an ad-hoc wi-fi network with the Pronto. The RFX9600 is not capable of 'Standalone' and requires that you connect everything through router.

All Pronto devices use Wireless B mode. Hence, a B/G access point will be required.

Note that WEP128 was most reliable although not very secure compared to WPA-PSK which takes longer time to connect.