I’m not an expert on cruisers (or much of anything) but here goes. Sportbikes and cruisers have different engine configurations and characteristics. They aim to deliver power in different ways so that is not too surprising. Even bikes that share the same engine (Ninja 500 and Vulcan 500), the engine has been tweaked to deliver power differently. There is so much more to how an engine behaves than simple cc’s but that is a convenient rough guide. Which is why a 600cc inline 4 is one to avoid but 650cc twins are (just barely) recommended here.
Your problem is most cruiser riders jump straight onto 1000cc or more so you have a very limited choice in this. Even at that engine size I believe the power on a cruiser is manageable but you start running into serious weight issues. Don’t underestimate the number of times as a beginner you will have (or nearly have) a zero mph drop. The weight of the machine beneath you will go a long way to determining if you can hold it upright or not.
I don’t know if the machine you are looking for exists. You might have to give serious consideration to buying something not quite your dream bike so that you have an easier time learning. Ride it for a year then upgrade.