I'm using a simple, bolt-on, universal for BMW, 25mm 'higher' riser which does not move the 'bars back (except for the natural rearward position change due to their height difference from stock) and which fit our 22mm 'bar diametre. These are sufficient for me and my 176cm frame and allow the 'bars to fall naturally to hand. I'm also using an adaptor that extends the length of the bars internally to give me slightly better steering leverage. You can get the risers from Touratech and others. They clear the fairing and because they move the 'bars to a position just within the frame or sightline of the mirrors I have fitted the K1100RS mirror extenders, which I reckon should be retro-fitted to all K100RS models (currently on special offer from Motobins).
I decided against bar backs because they would exacerbate the remote-feel of the steering even further due to the rubber mounted handlebars. The dash pad has to have a bracket fabricated to allow you to continue to use it but it is easy if you simply drill a coupla small holes in the bracket you've cobbed together (mine is made from 40mm long x 15mm wide aluminium strap) and rivet it to the original mounting place. No hoses or cables were harmed or changed in the making of this upgrade. It's as solid as...
In combo they work a charm!