Cam recommendation needed

Very nice looking car!
If you absolutely must have a hydraulic flat tappet, this cam works pretty well in a street stroker.
CHRYSLER COMP Cams 23-227-4 COMP Cams Xtreme Energy Camshafts | Summit Racing
Comp shows a different part number than summit, a reminder to always check before ordering!
Xtreme Energy HI-LIFT 231/237 Hydraulic Flat Cam for Chrysler 383-440
But, good luck with hydraulic flat tappet lifters. If it were me, I would be looking at a solid lifter cam. This cam would play very well with what you already have together here.
CHRYSLER COMP Cams 21-230-4 COMP Cams Xtreme Energy Camshafts | Summit Racing
Xtreme Energy 230/236 Solid Flat Cam for Chrysler 383-440
Solid EDM lifters makes wiping a cam less likely than with hydraulic lifters.
CHRYSLER COMP Cams 2901-16 COMP Cams Performance Series Solid Lifters | Summit Racing
CHRYSLER Howards Cams 91718 Howards Cams Direct Lube Extreme-Duty Mechanical Lifters | Summit Racing
Either way, use the Holley 875. That engine will really want even more carburetor than that. As far as a converter goes, you should really talk to PTC or the like and order a custom tight 9 inch converter. They'll take the information from your combination and build a converter that will be light years ahead of any generic stall rated shelf converter. It'll make the car so much more enjoyable to drive. A little more expensive that an off the shelf converter, but worth every penny.