There are smaller pantographs for short arm systems. Be aware that as you quilt, your take up bar will eat up some of your quilt area. The bigger the quilt, the smaller the area as you get to the end. Some quilters will reload the quilt the other direction to finish a long quilt.
Digitech Patterns will print out your pantograph at the size you choose. It has default size (if you dont' choose a diff size) and a suggested size (that will tell you if you can go smaller or bigger. you still CAN pick them, but the design may be squashed too small or stretched too large). Becareful! I always want them ALL! lol
http://www.digitechpaper.com/default.asp
Pantos by Dave Hudson are usually a good bet for starting out. His have larger designs and not too much detail.
Practice will help you tackle the more detailed as you go. I would suggest getting a few 5 inch designs and practicing with them for a few quilts till you get a rhythm and some confidence. PM for me if you need a cheerleader! Been there, done that!