DK makes a 30mm stem that is shorter than most, light and cheap. Crupi has a 0 offset stem as well. I think reversing the stem will make the bike handle funny, but it will get the bars much closer.

Sinz makes a mini lever for 9 dollars.

Look on a chart from Dan’s or J&R for the crank length, but I would buy up since you aren’t worried about results. Most of the min cranks are expensive to replace every year.

I am trying to build a bike for my 3yr old so I have been researching for awhile.