I don't think there's a perfect solution.
Close is Road Angel Navigator 7000 with Memory Map installed and some OS maps. Cheap off Ebay. Not the best Sat Nav for the car though.
GPS Enabled phone 3G, Google Maps and whichever Sat Nav software, but would you want to strap it on the bike?!? And it costs to run.
PDA, Integrated/bluetooth GPS, any Sat Nav software, any mapping software and maps. Battery life is a downfall here especially with external bluetooth GPS module. You'll need an Otterbox or such to ruggedise the PDA.