Piedmont carries Dibond and a few cheaper clones. The generic term is "ACM" or Aluminum Composite Material. I buy a very nice brushed aluminum Dibond clone for about $81 for a 4 x 8 foot x 3mm sheet. Your distributor may or may not be willing to make precision cuts for you, but if so they'll chop up a 4 x 8 foot sheet into 4 or so pieces for about $10. Plan on sanding the sides for best appearance.
You don't really need a super laminator for infrequent use. I have used something similar to
this dirtball device with good success, although considering the general trend towards cheapification in imports who can say if the quality is still adequate. Word of warning...you should have 2 people available, and don't pause mid way in the process or you risk a visible dent in the print. A good motorized laminator with tensioned feeds avoids a lot of potential problems and that's what you should have for routine use.
Personally, I have very low confidence in adhesive bonds, and not without reason. I mounted hundreds of paper and RC prints to aluminum, stainless steel, and latex coated boards in the 70's, and every one of the surviving examples I know about has completely delaminated. Many of the hand mounted RC prints I mounted to foamcore a few years ago have developed bubbles, which is a problem that may trace to too much moisture in the print and backing at the time of mounting. Your laminating technique and materials need to be top notch to avoid headaches down the road.
