You don't say which cameras you are displeased with. I might submit, however, that you are being a bit too demanding. I have had and still have a number of cameras, from cheap wooden folders to upscale monorails. All of my cameras have had some kind of zero setting (a slot in the locking arms on the wooden folders, spring-loaded detents on others, etc.). All have been adequate for my needs as far as alignment goes.

How precise you need to be in reaching parallel seems to be the issue here. I think that you will find that you need a lot less accuracy than you think, especially with wide-angle lenses. For me, getting somewhere close to parallel is fine for set-up. After that, I focus on the ground glass.

First, everything you need to ensure your negatives are focused as you desire should be on the ground glass (that's why it's called a "view camera" after all). If you want to agonize over something, then it should be the placement and alignment of your ground glass with the film plane and the alignment of the grid on your ground glass; these are worthy subjects for anal retentiveness

That and correct placement of the camera back (i.e., parallel to what you need it parallel to) are the most critical parts of composing a shot.
But, if you have your gg correct, you can find parallel by looking at it (verticals and horizontals in the scene should line up with the grid as you wish them to).

Similarly, focus is right there for you to see. I always check to make sure my desired plane of sharp focus is sharp, and then adjust to compensate, by tweaking the lens standard just a bit if I have the back where I want it.

I often notice, especially with some of my wooden folders, that when I use a lot of front rise and the bellows are rather compacted, that the pressure often pushes the front standard out of alignment a bit. I simply re-align it to parallel using the ground glass as a visual guide.

Come to think of it, I would likely work almost as efficiently with a camera that had absolutely no provision for setting things up parallel. I'd simply eyeball the setup (you'd be surprised how accurate you eye can be) and then deal with everything using the gridded ground glass and movements to position the plane of sharp focus.

One more observation. Any machine that is meant to be user-adjustable is going to have more slop in the adjustments than something that is machined solid, measured with lasers and micrometers, and fixed immovably at the factory. A Hasselblad has no issues with parallelism, but you can't adjust it. The inaccuracies and imprecision inherent in view-camera construction are the price we pay for flexibility.