I think there may be some confusion here about powering radios from the bike. The wintec cannot be powered though the autocom unit like some other radios (those supplied by autocom) but they can easily be supplied through a seperate 12V supply using a battery eliminator (supplied with the radio)
The Wintec is a very good bit of kit, works well with Autocom kit200 (Active Plus) or Smart 7 and Autocom will supply the leads to connect it. It will give much better range than the ICOM & Kenwood if you (illegaly) unlock it and increase the powere output.
As far as I know, the only supplier of Wintecs in the UK is Intaride. The wintec will usually work over about 4 miles but it depends on the location, buildings etc. Keep the aerial upright for max range.
Of all the riders I know the combination that works best is autocom and Wintec.