57 miles over a highly reflective path is just not a good idea. Too much height needed for clearance and multipath will kill you even if you can afford the structure.

There is not enough information here to give a response that is any better than saying flip a coin, or just pick the least expensive option. So I'll point out some of the decision points and ask you to fill in the blanks. The answer should start beco...

The real issue in this comparison is the service level you'll get from the ISP. All ADSL contracts are best effort with no guarantees. If any packets are passing many service providers will look no further in troubleshooting degraded ADSL service. ...