I looked at the assembly instructions - the bows are each two segments of aluminum tubing joined by an overlap and secured with a couple self-tapping screws. So I'm going to cut three segments of aluminum pipe and wedge those into the bows making the Bimini a couple inches wider so I can use the mounts in the factory locations.
Def am going to use support poles for the rear -got some on eBay for 70 bucks including shipping. They are Taylor-Made and adjustable. Thanks for the input!