Welcome to the forum Paul, you'll find the members on here are a friendly and helpful bunch :)
Sorry to hear of your spinal injury. The s line seats are a sportier design as apposed to the second seats. The s line seats have more side support and leg support. I think your easiest option would be to get leather electric se seats which will bolt straight in. If you've found these more comfortable then it would make sense as im not 100% sure that a8 seats fit.
Cheers
Steve