After alot of time researching and reading this forum I have decided to purchase the Liberty 643. I appreciate everyone's input. I also realize that noone here has admitted to buying one of these yet. I have had several conversations with two of the guys at Liberty. I also strongly considered gushman's reccomendations that this is the same as the xb600. The guys at Liberty have told me that the owner travels to China a few times per year. He had these made to their specifications so I do believe it has a bigger motor with a lot of the same parts as the xtreme. Veloteq also has a bike that looks exactly like the xb600 with a 500w motor and they are getting $1,500. The people at Liberty are very helpful and seem sincere.
The guy I spoke to said he has personally traveled 40 miles on one of these at low speed not accelerating fast or going over hills and he weighs 180 pounds. We will see about that. He said the speed tops out at 22mph. I should have it by early next week and I will post pictures and a full report.
The people at liberty also said they can get me a 60V controller and it would be easy to upgrade to 60v. I plan on using 5 35ah batteries to see what kind of range and performance I can get. This will be done by the first of the year.