Just to give you a comparison of sorts.....I have a Racer Brown SSH-44 for a Hemi sitting on my shop shelf. It's a hydraulic 292* .510 lift cam that Direct Connection had 30 years ago.
The reason it's on the shelf is for the very reason's you have pointed out in your post.....NO vacuum, pig rich running at idle and low speed, and all the other associated woes that a cam like that creates.
My hemi car doesn't have Power brakes,but the 6" of vacuum that I had wouldn't have run them anyways.
My is you need a cam down in the 276*-280* maximum (Not at .050 either)

That cam made the car haul like hell up top, but you couldn't poke around town with it and enjoy the car.
Just the stock solid in the car now, and that's what's staying in it.