Do any 3G routers run Tomato and still support 3g?
Asus RT-N12 with TomatoUSB
almost any broadcom SOC based router with an usb port running tomato can support a 3G usb dongle.
I haven't heard of 3G dedicated router running tomato
Asus RT-N16 Tomato Shibby build5x-101V
TP-Link TL-WR1043ND v1.8 - Openwrt 12.09beta
TP-Link TL-WR703n v1.2 - Openwrt Attitude Ajustement
Asus WL-500gP v1 - wl500g.googlecode.com rtn-r3702