Engine switch

Hello guys,
I got me a sweet 93 2009 convertible with under 100k km on it. The car is like brand new. I would like to replace the 150hp engine with V6 2.8T. How much would that cost, is it possible, does the chassis need altering as well, do I need a new gearbox?
Any kind of info would be a lot of help.
Current engine is B207E with automatic transmission.
Thank you upfront!
Cheers

Do you have pics? That's a pretty ambitious mod. Have you considered how much more Hp and Torque you can get out of the current B207e or switching with a B207R and larger turbo? Wouldn't imagine the LP9 engine would fit w/o significant mods. But where there's a will, there's often a way.