Welcome to the forum! Most sleds as early as 1990 came with hand warmers, if the sled doesn't have working ones, it's likely the element is bad or wires have broken. That's pretty common. New Polaris elements are about 30 bucks from the dealer, you may be able to find generic ones at places such as www.denniskirk.com
Look at DK for clothing, too. Also hit the ski swap meets, often ski gear can work for sled stuff until you know what you want. Manufacturers also have last year's stuff a little cheaper, too. You are right not to buy cheap, there's nothing worse than being cold and wet when you are out in the elements. And we do this on purpose!