Yeah twins are the way to go, the A series is meant to rev high properly setup, you'll get more power out of twins than you ever will with a single of the same (or the 32/36). You will notice a night and day difference going to twin sidedrafts. I fell I have some experience with this as I've ran them all. All on the same engine I started out with stock carb years ago, then switched to 32/36 DGV and it ran way better, then switched to twin SU's (GX setup) and it ran even harder. Finally went to twin 40mm Dellorto's and freaked out how awesome they were. I didn't lose any low end grunt, and my quarter mile times went from 19's to 15's, but that includes a couple other mods too :) (lightweight flywheel, ported/polished head, bigger valves, MSD ignition, electronic fuel pump/regulator, chrome-moly pushrods, headers). I ran each setup for at least 2 years a piece and would never go back to any of the others if I had a choice, but I haven't tried injection yet..that'd be next if I stuck with A15

The only problem is each setup required a little more and more tuning/maintenance as i progressed. If you can get the Webers set up and tuned well, it is SWEET. If you can't afford, run it in with a stock carb or cheap replacement and just save up a little longer for those twin sidies!!!!!! Or maybe the Matsuoka MSR Flat Valve carbs....yum.
-Andy