Also, BTW, if you're looking to save money --- forget the vinyl --- go buy half or a full cowhide in the color of your choice direct from an upholsterer's wholesale shop (or your local bootery supply --- lotsa those here in Texas). Most of the interior is nothing but flat panels of vinyl or leather that can be "slowly" peeled off. Then use those to make new patterns on your "cow" and (if it was leather especially) add an inch or so around the pattern to account for previous or future shrinkage, then just glue it back on with 3M upholstere's spray-on glue. For about $100 or so you've got a new leather interior and that great smell!
As for the seats, you'll want that done by an upholsterer to match. Personally, I replace my facings (where your fanny goes) with a contrasting-colored cloth. I find that is always comfortable no matter what the weather and looks especially good if I use 2 complimentary colors for the various panels. It doesn't cost much more than all one color snce they have to stitch it up in panels anyway (or maybe I've forgotten that the later models have panels where the earlier ones don't... hmmmm). Cloth facing is just my preference --- to each their own.
I've done my Targa's this and gotten by for about $1000 for a complete interior redo.