I have a 875 and love it. I got it Oct. 09 and discovered the feed dogs wouldn't stay down when I was trying to quilt. the LQS did everything they could to fix it but couldn't so the machine was replaced. The replacement has been a dream. I too bought a walking foor and a spring action quilting foot. The Phaff(sp) machine apparently has the walking foot built into it. whatever you get, ask where the machine has to go for service. It's best to have the service done at the shop you bought it, so you won't have so much time without your machine.
good luck