Sean,
I'd looked at the Cobras but had already commited to the OMP Brands Hatch. The Cobras are better for a 911 as they have the raised front bolster, which are better for the low driving position in the Porsche.
On the Beemer front, yes I took advantage of the poor Eire economy and bought this ex UK '74 tii in Dublin a few weeks back. Very pleased with what I got for £3500, as it was restored a few years ago by Jaymic, the Norfolk 02 specialist, and it only needed a small piece of welding at the rear spring mount.
Getting it ready to rally with Konis, stiffer springs and a trick LSD

Just in the midst of importing it at the moment to get it off the Irish ZV plates. MoT on Thursday, then I have to plead for an age related NI plate as the DVANI won't let me reclaim its original GB plate here