It's Time For the Descent Games Return
I loved playing Descent. We had our first LAN party back in the day with that game.
Recommendations for Cellular Signal Repeaters?
Speaking from a sales and Installation experience, the JDTeck at http://www.jdteck.com/ line of Active Cellular repeters is the best bang for the buck. $695 retail will get you the JD65-XT which is a full-duplex active repeater, allowing up to 20 simultaneous calls. I have installed 3 of these units for various customers and have had excellent results.
When I call to order one they ask the Zip and carrier and will do a tower location to find the best frequency for you and send it along. It is a full kit with a flat panel antenna for 1900 (PCS) kits or a directional Yagi for other frequencies.
Keep in mind I set these up in a rural environment with distance to tower being 3-6 miles. But this sounds like it would do the trick for you.