Just come across the AMD FirePro S9000 which seems to be a very close match to the D700 (slightly lower TFlops):
http://www.amd.com/uk/products/workstation/graphics/firepro-remote-graphics/S9000/Pages/S9000.aspx#3
Price wise it is also much closer to what Apple is charging than the W9000 i.e. at Scan in the UK it is £1710 inc VAT whilst the W9000 is £2,765.28 inc VAT.
http://www.amd.com/uk/products/workstation/graphics/firepro-remote-graphics/S9000/Pages/S9000.aspx#3
Price wise it is also much closer to what Apple is charging than the W9000 i.e. at Scan in the UK it is £1710 inc VAT whilst the W9000 is £2,765.28 inc VAT.