If the home you purchase is bank owned. The bank will require a proof of funds letter from a bank or brokerage firm. The name on the contract, to purchase, proof of funds letter and title/deed must all agree.
You will need to transfer the funds into an account that your son is on, prior to making an offer on bank owned. properties and possibly a short sale as well.
As far as buying a house with cash, if you buy it you can put the house in anyone's name you choose - it's yours to sell, trade, or give away.