I've done SID on a regular machine witout any problems. I do like using a walking foot; it does make a difference.

You can get a foot that has a guide down the center for stitch in the ditch. Like a little rudder that goes into the ditch. I haven't tried mine yet but it looks like it would help a lot.

Have one used it once...like the walking foot because it moves the fabric on top and botton and you don't get bunched up fabric you have to pull out...I found with the foot with the rudder I got allot of bunched fabric and pulled allot of stitches...

The key to a decent SID is:
1. a well-pressed back (hopefully with the seam on the same side.
2. a nice taut sandwich so there isn't much puckering.
3. starting in the center row and working out from there.
4. sewing on the low side of the seam and pulling the seam line apart slightly so you can get a good sense of where to sew.
5. going slow and steady.
6. when the seam changes direction, simply let the needle move over (it's only or or 2 stitchs) to the low side of the seam and continuing on.
7. using a walking foot helps but isn't necessary when the other steps are followed.

do you know the name of the foot in question.

Do you mean the walking foot? It's just called a "walking foot" and you have to make sure to get one that will work with your machine. They are not generic. Unfortunately, they are not cheap either, but I think they are worth it.