they're so similar there is hardly anything in it. firstly stomp and wpb are the same company selling the same bikes with different stickers on, but ultimatley the same comany.
the wpb bike is a crf70 style the stomp is 50 style, but they're near identical bikes, your better off choosing which one you like the look of best or which one fits your wallet best.
the 50 style bike looks like it has outgrown it's bodywork a little but that's typical of mos crf50 copy bikes.
both of these bikes will take a certain amount of abuse but in the long run you'll end up looking for better suspension. everything else will be ok for you.
tbh your better of buying fergals bike and spending what you save on suspension upgrades. don't get hung up on having to have a brand new one cos it'll end up in a state the first time you ride it