Buy what you want – the Boxster has consistently been reviewed as one of the best sports cars out there, not because it’s the fastest, but because it’s usable every day, has a great ride, handles UK roads well and offers a great driving experience to the driver.
The japanese cars may outpoint it in lots of specific areas but none have come close to it (Z cars ride too crashy, Honda’s too peaky in power delivery)
The only japanese sports car that doesn’t outdrag the Porsche is the only one that’s highly regarded as a drivers car (MX5) – it’s the one to buy if you can’t afford a Porsche (take a look at the BBR 20th Anniversary MX5)
As for ‘poor mans 911’, if the boxster wasn’t conceived it’s probable that Porsche and the 911 would have gone down the tubes in the 90’s.
I’d probably go for the 3.22 if it was me – you’d always be wondering if you should have bought it if you go for the 2.7!