...My boss has a liking for things that go fast and are new, and will no doubt end up with a CJ1/2 or similar one day....
The other options for a new piston twin are the G58 baron and Seneca. Im endorsed on both and with The G58 costing $1.5M+ and having less useful load than the P68 and burning over 130 Lp/h it doesnt make any sense.
If you're boss is even entertaining those sort of numbers and has a discerning taste for speed and comfort then I'd suggest that you get your boss a demo ride of some sort on a Kingair. Faster, more comfortable and much nicer to fly than anything else mentioned and pressurised to get above the weather.