I finished my first synthetic quilt a couple of weeks ago, a summer bag with 2.5 oz Climashield Apex and I am right in the middle of a 3-season bag with 900 FP down. If you've already successfully made a tarp and things, then you can definitely make a good quilt. Synthetic quilts are very easy, and so far the down quilt has been rather labor-intensive but not too difficult. Just a lot of long, straight seams. Way easier seams than apparel or some backpack seams.
I got my materials from Thru-Hiker - Momentum90 nylon, noseeum mesh, and down. They're nice to work with.
I second the links others have posted. Jamie Shortt's article is great. I've also been referring to the Neatoman quilt article:
You can definitely make one...go for it!