Regerstration in ohio for a Brit
 

I have a friend staying with me from the UK he is on a UK licence and is wanting to buy a bike in Ohio privately,but needs to register it there and insure it! he has a friends address to do that but what other problems does he need to overcome so he can continue on his ride to S.A?Is he able to get a USA licence and to register it without being a citizen or having residency for the USA.Please advise asap as he has located a bike in Ohio.
Thanks Andy.