You can run the EF block & head using the EA MPI Manifold, injectors ECU etc.
I'm not entirely sure, however, the engine mounts should be a straight bolt up as well.
This would work out pretty cheaply compared to doing a complete rebuild of an EA donk, and getting it balanced nicely.
As for the engine work. If you don't use an EF/L engine, you should seriously concider using an EF/l head, or better still, an XR head. This will give you a better building block as the valves are bigger, as well as the port diameter.
If you use the standard EA head, it will need quite a few hours at the die grinding bench to get her flowing nicely, which in the end, costs you more $$$.
The zorst setup in my car is pretty quiet compared to others I hear driving around.
On idel, she gives out a low burble. While cruising, its just noticable, minimal drone, but at full stick, she make a bit of noise, nothing too bad.
I use Motivator 6>3>2>1 extractors with a 3" pipe into the CAT, then 2.5" mandrel bent zorst (Redback) with a high flow muff and one sports resinator in the rear.
Since your in Melb, you might be better off having a chat to Jim Mock.
CAUTION: Slippery When BOOSTING!