The Sonnet Echo Expresscard Pro + PE4L 2.1b is a 4Gbps (after overhead) Thunderbolt-to-expresscard solution that costs > US$230. This solution was the best value a number of months ago but isn't any longer.
Now there is a new Firmtek Thundertek 10Gbps enclosure available for US$199. So you can get more than double the bandwidth for lower cost. Only negative is a pcie riser is needed to extend the x4 slot to a x16 slot. Details at http://forum.techinferno.com/diy-e-...sonnet-echo-express-iii-d-win8.html#post91184
Thanks for the advice nando4, I think I will upgrade to either the Firmtek or the full Sonet chassis in a few months/wait until more TB3 details have been announced.
I think I will aim to use a mini-ATX chassis and stuff everything inside that