Fire hoses typically have NH/NST threaded fittings in the U.S. although there are other types so look for NH or NST listings (they are interchangable), you typically need an NH or NST to NPT adapter , these are available in polycarbonate or brass for as little as about $10 on ebay. 1.5 inch fire hose is very common (most building hose cabinets use these), and often available in 50 - 100 ft lengths "used" on ebay, these used hoses often spent their whole life never being used in a cabinet and were replaced due to age, by fire code these must be replaced or recertified after a certain age (I think 20 years), so they tend to sell cheap on sites like ebay. Often asking prices / auctions will vary considerably, but you should be able to get one under $50.
Ike