Datacolor User to User Support Group.

I've found i've cut up about 100 A5 sized Canon Photo paper pro and can't find anymore A4 size from the same batch to profile. Can you pls advise how i can profile these A5 size paper? I'm guessing that i can use the 225 patch CD target files (4 of them) and print it through Photoshop CS5 - right? I can resize these to fit the A5 paper but i'm confused about the correct printer settings in CS5 to use to print them out without any profiles. This is my proposal - tell me if i'm wrong: 
Color management - set to Document (Profile: Untagged RGB), Color Handling - Photoshop Manages Colors, now i'm stumped at the next one.......reading previous threads CD TOBIE recommends i choose a printer profile. Is this correct? It doesn't make sense at that part -what if i chose the wrong printer profile - wouldn't that make the patches come out wrongly.

another question - assuming i've successfully printed the patches out correctly - how should i read them and through which part of the v4.1.1 Spyderprint that'll enable these 225 x 4 patch readings?

Thank-you.