Speaking as someone who does a lot of FMQ AND sews up horse (mule) blankets on a regular basis, I don't think there is a perfect machine for doing both tasks. I use a Juki TL 98 for quilting and have a Chandler upholstery machine (any brnad upholstery machine would certainly work) that i use for sewing up those heavy, thick blankets. There's just no way a domestic machine can handle the thickness of canvas or cordura PLUS lining PLUS strapping PLUS that thick edge binding used on horse blankets. On the other hand, the upholstery machine powers right through it. You should also be using MUCH heavier thread and larger needle for horse blankets than you can/should use on a quilting machine.
So, my advise is get your dream quilting machine, and let them get what they need to sew up horse blankets!
Wendy