Well, does the autocrossing are you doing allows such a wide rule interpretation to use such a combination? Most SCCA based classes I've seen are so restrictive to prevent this type of mod.

Rack width and travel to much such an arrangement would be a big concern to me, otherwise you are introducing the potential for as bad or worse bump steer characteristics as the stock rear steer.

FWIW, Firm Feel was working on a pretty trick set up using 73+ B body lower arms and a variety of aftermarket parts. I've seen pictures of it before, but don't recall where. You might try searching around to find something on it and gleen some ideas form it.