I would just burn the JPG's to a CD - At the shop let them know that you would like the print size to be - width 10.8 X height 7.293 @300 dpi.
AND Yes when printed on a bad-a$$ laser printer (like the Fiery XJ) the DVD cover look G-R-E-A-T! VERY real and VERY Professional!

Here is the specs on the cover sizes

All keepcases use the same size cover for the front and back 'the face' (1535 x 2188 pixels), the only thing that changes is the spine width.

COVER SIZES + SPINE SIZE

single: 3240 x 2188 pixels (spine: 170 pixels)

double: 3305 x 2188 pixels (spine: 235 pixels)

triple (slim): 3384 x 2188 pixels (spine 314 pixels)

4/5 disc: 3508 x 2188 pixels (spine: 438 pixels)

6/7 disc: 3661 x 2188 pixels (spine: 591 pixels)

ThinPak single: 3150 x 2188 pixels (spine: 80 pixels)

ThinPak double: 3172 x 2188 pixels (spine: 122 pixels)

CENTER MARKS

full size = 1535 x 2188 pixels
Vertical quarter mark = 547 pixels
Vertical center mark = 767.5 pixels
Vertical 3 quarter mark = 1641 pixels
horizontal center mark = 1094 pixels