Off the top of my head I suspect the SV is one your favourite bikes, you seem to have owned it for at least 2 years.
You have tried the Triumph route, the Harley thing and various other cruiser things.
I would find a decent seat fabricator local to you and ask them make you a seat that addresses the 'nad crushing on the SV. You could also look at moving the pegs and controls. With time on your hands how about looking into a Strom seat and tank unit being modified to suit and again alter the pegs and controls to suit.
I can't for the life of me think of a single bike review where the original seat was described as "plush", I have yet to meet anyone who has a bike and the stock ergos are perfect. (I'm including screen, bars, mirrors, seat and suspension)
Something like this?