Recommendations for wireless router for my work

I am a physical therapist, I work in a large clinic (total of 14 treatment staff) that are all working on laptops with our Electronic Medical Records (EMR) program. The router we currently have is waaay too slow, its an old Linksys WRT54GL that only supports wireless G (!!!!).

Needless to say, our connectivity to our EMR (which has a local client but information is stored server-side I believe) can go in an out, resulting in maddening loss of entered data when writing out physician summaries and daily notes. We have a Comcast business connection with 50mbps down, 10 up (I think). So speed shouldn't be a problem.

Our building is rather big, about 5,000 square feet, and we have two them next to each other. We currently have separate routers in each building that are on the same network.

I am looking for a wireless router that can support all the bandwidth of 14 individuals documenting at once as well as having good range while not breaking the bank.

I figured this would be the best place to seek recommendations. Thank you for your time!