Thread here (on this forum) should answer your cartridge question:
http://www.ducatimonsterforum.org/index.php?topic=66649.0Unfortunately the answer is that the 796 is different.
Andreani seems to offer an installation service
at this link, but at $1150 euros it is not cheap.
Ohlins dealer
Fast Bike Industries in Hendersonville NC says it handles Andreani stuff in the US. Maybe they can help if you want to go this way.
There is a brief but very complimentary comment about half way down
this page at ducati.ms from a member who fitted an Andreani fork kit to his Sport Classic.
On the shock, I am not sure what you mean by an Ohlins 46 DR but
the Andreani site offers an Ohlins S46HR1C1 which is a proper remote-reservoir shock that will either work beautifully out of the box or can be revalved until it does.
Another good option might be to contact
Rick at Cogent Dynamics, as he is well experienced with Ducatis and could have some advice about getting a good result without spending the earth.
There you go ... a couple of helpful posts for a newbie with a post count of one.
I hope you have some success - and stop in here and let us know how the search goes.