My vote would be to steer away from TS and use Access front end using pass through to SQL Server backend which would probably be the quickest, easiest, most cost effective, and most maintainable solution. Here's why:
I know nothing about the state of your user communities workstations, but Access front end would probably run better than .net on non cutting edge hardware. If your WAN is good it would be hard to beat for speed or at least that's my experience. I think but i'm not an expert in that area that hardware and licensing to support 64 users on TS would be more expensive and harder to maintain than SQL Server (Express). If Express wasn't strong enough and you had to go full SQL Server then licensing would be offset but hardware costs would still most likely be higher for TS.
Jim