SU Conversion for series 3

Firstly,
Hello as a new user,I have acquired an SU Carb from ebay for a song,but sourcing the inlet Manifold/conversion piece is proving nigh on impossible!
Does anyone know of somewhere I find one without spending huge amounts of money?
Thanks in advance
Tony

I made mine myself, it simply bolts to the original manifold instead of the webber that was on there, and has the SU bolt pattern on the other side. The SU I got from a metro already had a 90 degree bend in it to mount to the metro manifold, so everything turns up the right way round. would be more challenging to make a whole manifold mind. Only place I ever saw them would be ACR, who do the SU kit, and a rumour that the head pattern was the same as a TR4 so a manifold form one of those might work, though treat that information with the mistrust it deserves....