Without knowing what's inside your enging, it's a little tough making recommendations. The fact you're running a stock carb likely means your running a stock 1600 engine. So obviously the most reliable will be a stock Solex pict 33-34 carb. Bill K runs this setup.
For a little more oomph on an engine up to say 1835 or maybe 1915, you can go with dual Kadrons like those available from the likes of AJ Simms (although I would bet several of our sponsors could set you up.) The Kadron setup is made up of 2- brosol-solex, single throat 40mm carbs. I have that setup on my 1776 (with 009) and love it.
You could as easily step up to the dual Weber carbs but they would need to be tuned quite lean for your stock (assumed) engine, as the Webers are quite a large carb and generally work best larger displacement engines (1915 and up.) If you have future plans to rebuild and boost the displacement of you engine to 1915 or above, I would strongly consider the Webers as they can be re-jetted for the larger displacement. I believe that Weber does make a single throat carb similar to the Kads.
Hope that helps, the opinions are my own
