What size bike and brand for 3yo

[Suedeyt]

My 3yo currently has a 12inch but doesn't like to ride it any more because he has to pedal so much and barely moves. I have been looking on marketplace for a 14inch but can't find any but there are alot of 16inch available is that too big for him?
If I do get 16inch what is a good brand? I see a lot of malvern star, we will be biking for 20 minutes on flat surface when we go for bush walks in the warmer weather so not needing anything special just want him to stay interested in biking thank you

[blizzard]

Second hand BYK e-250 or e-350 probably hits the nexus for price and quality. Check their size guide because the e-350 might be a bit big right now.