1997 DeVille - head gasket troubles - repair shop ?

Hello everyone, I'm new to the forum, my name is Dave. I recently purchased a 1997 Cadillac Deville for 4665.0 with 77,000 miles on it, body perfect, interior perfect, all the power works and the antenna still goes up down. I spent several months looking for the perfect car and finally found one that was in state, Colorado. I checked the car fax, and two thousand miles ago it had a new radiator and thermostat installed. I went to a very small dealership and signed the AS IS form and drove it off with a smile on my face. I think you all know what happened next. As the temperature increased, the smile disappeared. In all my research for the perfect vehicle, I failed to lookup potential issued with the car and when I did, I realized that I had taken my hard earned cash, plus two grand I borrowed from a friend and threw it away. After several weeks of maybe it's not the head gasket, I have finally come to grips with it. I spent a few more weeks going to mechanics and Cadillac dealerships trying to find a solution. I've had quotes from 1700-4000 to fix it. I could just dump it and try to not lose all my money but I really do love the car. I found Northstar Performance and after reviewing the website, I truly understand the issue, but it creates another issue. If i do want to fix it right I need to take it to NSP. I'm concerned that shops that don't have an understanding will just try and sleeve it, put me down more money and it's still not fixed. Are there any shops in the USA that might be closer to me, (Colorado) that would fix it too NSP standards? I thank you all for your time and any input would be greatly appreciated,

Dave