I have had good luck with older D-Link and Linksys WiFi G routers with UMA (and running separate VPN and VoIP connections). But sometimes I'd have VoIP and UMA problems while conducting a large download or big email files.
I've also used Linksys WiFi access points on a Edimax dual WAN router. Same issue with downloading and UMA, except you can force the UMA to the more lightly loaded WAN connections (via locking the Blackberry's MAC address to a specific IP and WAN port).
But for my location without dual WAN's, I'm looking for a router that handles UMA well, esp QoS and power management.
Should I get a newer D-Link from TMO? Or buy an old TMO/Linksys WRT54G-TM? Or???