Zhangjiajie in 3 days

I now have budgeted 3 full days in ZJJ so I will do the Grand Canyon on 1 day, the ZJJ park & scenic area on Day 2, and Tianmenshan on Day 3. We would like a to hire a private car and driver to take us to these places and wait for us while we visit so should be look for a guide and book beforehand or is it simple enough to hire a taxi (no guide) for the day for the areas on Day 1 and 2? We are staying at the Yijiaqin Hotel in downtown ZJJ and this is very close to Tianmenshan cable car so I don't think we need a taxi for that day. If everything is easy enough to see in these 3 areas do we need a guide or will a taxi be good enough? Or is a guide with their own car pretty much as cheap as hiring a taxi? We do not want to join a tour. Also, suggestions of a reliable guide (with car) that is not too expensive would be welcome.