Plan on building/& or getting built a stock appearing motor running a stock bore greyhound with a .175 arc stroker kit 356 lift cam. Wanting more power!
Are you asking for an opinion in that?
Or are you fishing for other suggestions?
You can buy a lot of things that simply bolt on for the cost of the stroker kit and you don;t even have to machine anything to use them.
If it were me....
I would look long and hard at predator 60603.
Use the 18cc honda head and sell the hemi to recoup some of your expense ( sell it here on the OldMiniBikes ).
You could buy a bored carb with the money you make from the head.
Then you need to buy some upgrades valve train parts and a decent cam for you application.
You need a flywheel and rod ( the standard honda arc rod does not fit predator 60306 you need to get the correct one for its smaller journal and longer stroke, but all other internal parts are the same )
You need buy expensive parts to build any engine.
You need a good plan to build a great engine...