I belive the Weber 32/36 dgv could be a good choice whith jets and venturies etc suited for your engine..
That carb open the secondary whith help of vacuum...Dcd open sec mechanic.
I do belive a Dgv 32/36 could be adapted whith right choice of vents and jets etc to work on a slant. Dgv is vacuum secondary.Dcd is Mechanical secondary.
My choice would be a Dcd.