Hi
Here's a link to the one my hubby did. The knee lift isn't fitted in these pics, but he's since fitted it and it's fine.
The needle is 11" back from the edge of the table for me. I sat so the machine was a comfortable distance and this seems to be ok. Wouldn't want it any further away...and even could be an inch closer maybe, but it's not a problem.
And no, I don't bump my knees at all.
http://www.quiltingboard.com/t-76568-1.htm