Either of those carbs you mentioned are fine, but you'll need to find a matched pair. Also I'd have them professionally rebuilt and throttle shafts re-bushed or they'll suck air and never run right.
NOS would be best or while they are not 'period correct' Langdon's has a great NEW Holley/Webber or Carter/Webbers that will adapt to your old intake, not expensive. You can check them out at Langdon's Stovebolt website.
I wouldn't worry not having the 848 head, for a driver what ever you have will be just fine.
