Kz400 Single Carb Conversion

One of my carbs on my 79 kz400 ltd. is acting up and im pretty sure on its way out. I was thinking of just converting my bike to a single carb and fabbing up a stainless 2 to 1 manifold. Wanted some input on what might be a good carb to replace my two.

Any carb 32-35mm because you will have to rejet it and anything bigger or smaller the jets needed wont fit. I thought i could use a keihin 38mm but no...too rich. Sucks.