Rich Johnson fabricates a lot of 914 (-4&-6) specific hardware.. and is upfront and honest to deal with..
he not only makes that boxster setup, but also makes the 2-1 brake line adapter i used in order to fit the Volvo 4 piston calipers to my 914..
granted you're not getting monobloc brakes, nor are they Brembo.. but they *are* 4 piston, and have bigger surface than any of the *normal* Porsche brakes (the non-brembo line).. and.. here's the biggy.. they cost 20 dollars at the local junkyard..
i don't want to search for my posted links re: my brake setup anymore, i think it's earlier on this thread.. the interested party can look it up themselves..
Jeff