Opel Carb
Gary's right, the best overall carb for a stock engine is the DG_V series. The 38 DG_S is really only suitable for higher output engines, as OpelMeister RallyBob has said. I have been told that the "A" (water choke) is best for cold climates, as it makes the choke respond to actual engine temperature, while the "E" (electric choke) is generally easier to install (no messy heater hose connections) and works pretty good, even in moderately cold weather applications. Probably fine for balmy southern Ontario, less so for Northern Saskatchewan. I happen to have a manual choke, which fits nicely into my "control" oriented personality.
As for the DF_V series, I actually happen to have a 32 DFM on my GT, which has the primary on the wrong side and the rotation is reversed. It has 32 mm throttles on both sides, but is a progressive mechanical versus the vacuum operated secondary on some applications. It REALLY pissed me off when I bought it (24 years ago) as I needed the car the next day, the shop where I bought it was closed, and the Solex was toast! A girl thing, as I recall (Life Before Myrna). So I worked all night, figured out how to reverse the bell crank, and made a fancy offset pin for the carb lever. I have read that this style can lead to leaning out due to the intake manifold design (RallyBob again) but mine has been in service for at least 15 of those years and 55,000 miles, many of them at high speed and full throttle, without a burnt valve or other misadventure. But the throttle rod is at a bit of an angle, and the pin is a bit bush, so I will probably fork out for the proper carb on the next engine upgrade. But it works MUCH better than the old Solex! And it generally can be found easily and cheap, since they came on early '70's Cortina GT's (the DFAV, at least) and some other domestic applications, including the pitiful Pinto.
HTH