Frames (Style P1 is the least expensive)
http://www.framingsupplies.com/AluminumFrames/AlumimumFramePage.htm
Acid Free Foam Board (1/8″ foam board should be fine) – can be cut to size
http://www.framingsupplies.com/MatBoardFoamBoard/FoamBoard.htm
Crescent Rag Mat – can be cut to size for an extra fee
http://www.framingsupplies.com/MatBoardFoamBoard/Ragmat.htm
Hanging WIre (scroll to the bottom of the page for smaller quantities (you all may want to go in on a single roll of #6
http://www.framingsupplies.com/HangingWire.htm
1.25″ Self-Adhesive Linen Tape
http://www.framingsupplies.com/ToolsTapesGlues/ToolsTapesGlues.htm