[Roadsters] Solex carbs

[Tim]

Now that I have a basic understanding of the SU carbs, let's add to my confusion: 

What size Solex Carb(s) will work on our Roadsters; both the 1600 & 2000? Does each size Solex Carb require a different intake manifold or is it a one size fits all as far as intakes go (I realize that the intake manifolds will be different sized between the 1600s & 2000s)? Are these manifolds available or have they passed into the unobtanium realm? Are the Solexs that fit the Datsun Roadster "exclusive" to the Datsun Roadster or do they work on other models as well? 

Thanks

Tim