Its possible to have an 'Adventure' type seat.. i.e. a single piece seat. without any changes whatsoever... just keep your eyes peeled for a Touratech. I managed to grab one - an eBay bargain. They do occasionally appear and for some odd reason get very little interest. I guess because they look quite different with the original 'suede-like' cover... that didn't last long.
Photo is old - my bike has undergone rather a lot of changes over the years, i still have the seat though - its rather good.