Avram has a line on a cheap 911 engine, to go with his breadloaf.  This is
a great start, but you don't want to picture the swap as taking just a "few
simple adjustments" as tho the two engines were exchangeable modules.  The
Porsche engine has about a 10-quart oil tank that you need to cut a spot
for, and the spot is where your battery used to live, so that moves.  You
need a $300 adapter flywheel from KEP.  You may need to reroute your
accelerator cable, you may want an external oil cooler, and you will have
to invent a rear engine brace.  On the breadloaf, you will probably have
to cut body metal and/or move the bumper out to clear the Porsche muffler.
I'm not saying it's not worth it; it is.  Just that you have some planning
 and shopping still to do.

Keep the list posted on your plans and progress!
B.