If it can push this around
http://www.eastcoastrover.com/NAS337/Final.jpg he shouldn't have a issue.
also will want torque not HP with his gearing and depending on the t-case or t-cases he should be ok. Again will come down to the cost of things.
They are not hard to do I looked into building one on our deck. If you are doing a true pergolas make sure you do it with 6x6 post as 4x4 will not look right.
always use Fedex and have it set so someone has to sign for it even if it cost a little more its the added step of piece of mind that you can not get fucked over.