Configure Hotspot On Router

I have a Linksys WRT54GL behind an internet connected 3G router using mobile broadband dongle connected to the USB port (not fixed line broadband) on a TP-Link TL-MR3420. I have version 1.0 and version 1.2 models of the TL-MR3420. WRT54GL currently has a recent OpenWRT firmware and the TL-MR3420's can also have OpenWRT firmware. Required: Phase 1: Full featured Hotspot system to run on the WRT54GL which is connected to one of the LAN ports on the internet connected 3G TL-MR3420. Port forwarding or whatever it is may be required between the 2 routers. Phase 2: WRT54GL to be removed from the system and hotspot to run directly on the 3G TL-MR3420. Even though I have flashed OpenWRT to one of the TL-MR3420's I haven't had the 3G USB port running as with the firmware (think it is supported though from what I have read). Hotspot system ideally to be one of the fixed cost systems rather than revenue share based systems. Please give your suggestions as to which Hotspot system I should use. I can send better formatted information on the 2 routers if required. So price for phase 1 and then a follow up price for phase 2 based on capability of each router. Would like both phases of the project to be completed asap.