Hi, Thomas!
You're most likely overwhelmed with all the input, but here's my two cents, as well.
I've used Singers (not for quilting - I learned to sew on them), Kenmore, New Home (now Janome), and my current Machine is a Pfaff Expression 2038. I love it because it's quiet, sews easily over the 3 quilt layers, has a couple of quilting stitches in addition to almost any number of decorative/fancy stitches a sewer/quilter could want, and the best part of it is the IDT foot (integrated dual feed). You can call it a 'built-in walking foot' - that's how it was described to me -- and it feeds the layers evenly through as you are sewing - no puckers! At least I haven't had any!
My machine was $1,600, but I do know Pfaff has many machines and I'm sure you would find one somewhere in you price range. the best thing to do is take your wife for a 'test drive' and see what she likes....
Comments on my other machines? I loved them all, especially my New Home Memory Craft 6000, but I used it well for over 20 years, and the computer started going out, and the nearest Janmome dealer is over an Hour away. My Pfaff dealer is only a 25 minute drive, and great service.
Good luck on your shopping expedition!