There are some older threads on modifications for the Ken Lund frame. Here is a link to one:
http://www.quiltingboard.com/main-f1...e-t195959.html
If you use the "search" box in the upper righthand corner for "Ken Lund" you may find more.
It seems to me that you need a wide and long table that is fairly low. Do you have an Ikea store anywhere near you? I think you could find what you need there, as they sell table tops and legs separately. For a chair to slide around, I would get either an armless office swivel chair with pneumatic lift, or one of the dentist chairs off eBay that sell for around $40 (considerably cheaper than similar "saddle" type chairs sold for quilting). Here is a sample dentist chair:
http://www.ebay.com/itm/Footrest-Sad...item43c9ab4493