I considered buying a 1.6 and swapping the engine for a mi16... But in the end I chose the 2.2 as it offered more power right away... and, knowing me, I wasn't sure I would ever get such a project done, as its a bigger project then first expected!!.
To the best of my knowledge no one here has fitted a mi16 in a Murena... but at least two has swapped for a 1.9 8valve pug Gti engine.
Lennart had all the work done for him, but Bart_Maztra, I believe, did all the work himself, so he might be able to help you... maybe he even has some pats laying around
Fitting the 16v should be much the same as the 8v.. though I think it is harder to find space for the inlet manifold, and It should be possible to get the xu engine in a murena without cutting and welding the frame... but its a huge project.. and bound to be more expensive then one expects... such projects always are.
It's not possible to simply swap the 1.6 for a 2.2! .. there are lots of differences between the cars, such as trailing arms, engine mounting points, anti roll bar, driveshafts, wireing loom and so on.
So if you want another engine, the 2.2 will be just as difficult to fit as a m16.
I would trust the chassis to cope with 200+ hp without any modification... but not the standard brakes or suspension.