coloring book pages should be easy to digitize. there is a free download for digitizing. stitch era i think its called. it is fairly easy to use.

Embroidery Library has 103 pages of designs that come up when you search for "quilting". .I think
that about 1/3 of these are actually the quilting designs, not embroidered block designs.They are for borders, different block sizes, corners, etc. Surely you could find something that you could use. Or maybe not. Good luck.

Why not try a coloring book for your pattern and go from there?

It does exist. I think all of the suggested sites have some. Please don't forget that most designs when about finished... do an outline stitch that really berings the design to life. If you advance to that point...Wala...there is your outline design.

You could try here: http://www.needlepassionembroidery.com/index.htm
I love her designs, I never had a bad stitch out from any of them, and I have used many of them. Her machine quilting design collections are near the bottom of the home page.

While I'll admit these are really pretty, I'd go bonkers doing them since they are only 4 x 4. I'm surprised they aren't offered in larger sizes.

I see Adorable Designs just came out with some cute outlined baby designs that can be used for quilting.

www.perfectlittlestitches.com I've used their quilt designs before with great success and recommend them highly. =)

http://www.oregonpatchworks.com/ has many designers and some vintage type outline designs also