If I would like to buy a two-way radio, where should I go?

Does any electronics store have them?

Best Answer:

Tempting Apple: A maritime shop.
And if you in the UK you will need to pass the maritime VHF radio operators course!

Other answer:

Tempting Apple:
Radio Shack
JetDoc:
Since you are asking in the category for Boats & Boating, I would think a marine supply store or a place where they sell boating supplies would be the logical place to look for a marine band radio.
CB:
Amazon – and you will need the appropriate antenna.