I've had about 10,3:1 compression on a 1.6 CVH MFI. No issues even when using standard 95 ROZ/RON petrol. And it's not about the power output, it's mostly about the torque. And to really gain power a combination of more than one modifications is a must.

Forget that carburettor fairytales. That's stone-age engineering. Bike carbs might be a common mod, but it's the same like any other carb conversion. Especially when the conversion is done by cutting the standard inlet manifold and connection the carbs with silicone hoses to it.
Bike throttle bodies? Not the worst idea, but it still will take a lot of work, money and skill to make them fit properly. And after all... all these mods work well with high revs and that's something the CVH wasn't made for. So sticking with a proper manifold and one throttle works well on most road-going engines.

Roller rockers and roller rocker arms? These will produce a lot of play, high power output engines in Europe never use things like that and the only standard engine over here fitted with roller rockers was the 1,8 CVH in the Ford Sierra. Problems with followers and cam lobes? This is a very common problem for CVHs with aftermarket (tuning) camshafts. When you think about buying a camshaft that needs to use things like cam lube or running-in oil... throw them as far as you can. That's crap and a sign of ancient machinery. Manufacturers/tuning companies with proper machines will be able to grind and harden the lobes perfectly so you just have to put the camshaft and followers in with standard engine oil. Start the engine and have fun. Leading companies like AVL Schrick are able to produce such camshaft since the 1950s or 1960s.

Adjustable camshaft pulley? Always a good idea. Even with a standard camshaft you'll be able to find a few horses as you can eliminiate factory tolerances, especially on such an old engine.

I doubt the head design of the CVH will be able to cope with high compression rates of 11:1 and more, no matter which kind of petrol you're using. Aim for a healthy 10:1, with a proper camshaft, manifold, exhaust, inlet and head work you won't have any problems reaching the 150 hp you're aiming for.

And as we're now in the computer age also think about throwing out the mechanical distributor. Having a mappable injection system (with ignition) will give you much more power AND possibilities than tinkering with the vacuum advance of the dizzy (which isn't the only part that affects the ignition timing).