Millisecond Forums

In what is sure to be a naive question (still new to Inquisit) - I'm writing a program to run online where participants rate images.  Each participant will rate 63 images, and there are 5 sets of 63 images that will differ between participants.  What is the best way to assign the image sets across participants?  Should all (5x63=) 315 images be included in a single program (I'm worried about loading times)?  And if so, how can I assign the different image sets to different people?  I've thought about making each set of images a different "item",  (e.g., <item firstsetofimages>, /1="image1.jpg", etc.) and then somehow write that in each condition to reference a different one of those item lists (e.g., /onexptbegin=[values.thisconditionlist="firstsetofimages"]).  It's not working the way that I'm trying it right now - but if anyone can guide me on how to assign certain images to different people - I'd really appreciate your help!  (Please also let me know if I can clarify the question.)  Thanks in advance!!