Yes as Rusty says the Dellorto I have is very good.
It over-fuels a bit and my fuel economy is questionable when you run it hard but floorless acceloration and the thing I like the most is the manifold gets the carb away from the head (heat) so all the fuel doesn't evaporate out the carb.
I tried a bike carb and had pretty good results with that, just wasnt happy with the mounting it was on.
One thing comes-up over and over again is that no matter which option of carb you go for, the best set-up would be to have a specialist put the car on a dyno and jet it from there.
Make sure all the work you want to do to the engine is done first.
For example with mine, it is scheduled for dyno once I have completed what mods I intend doing.
So far fitted carb, sporty cam, sporty exhaust alloy sump, alloy extended rocker cover to increase internal air volume up top. Electronic ignition that works fitted. Electric fuel pump fitted and plated where pump was, to be used as breather later.
Breather to be sorted with catch tank. Oil cooler to be fitted. One to one belt drive toothed, alloy fan and possible re-work of venting of the rear bodywork.
Dynamic balancing to be done and lightened flywheel with increace to 700cc
although I have seen bigger piston kits, 700 seems to be the most durable.
This may all be scrapped as I am tinkering with a double overhead cam 4 valve head..who knows if it'll blow-up, nothing ventured nothing gained but then I'll be after a delly 40 twin choke

But then there are a few other ideas the conservatory plans have put pay to..

I like the idea of the SU as mixture across the range is adjustable via the nut that moves the jet in relation to the needle. Smallcox has an SU and to be honest, I think the SU would be cheaper and achieve just as good results and should fit strait onto the aftermarket casting for the Delly FZD. Ceramics are available from a website in australia to fit the SU's keeping them nice and cool

Spares readily available for them too

There was a song in the 80's that went 'never ending sto-ory...la-la la la-la la la-la-la'