Fortunately most men and boys are pretty much built like that (broad shoulders, small chest, small waist) so you have a LOT of jerseys to choose from.
If you are petite look for companies that do clothes for boys/juniors. One of my favorites is a Voler XS. The euro-made jerseys are cut this way as well, but you are correct about the arm-elastic. If you lift and/or swim much they pinch! Try to find styles and brands that dont' have elastic or cut the elastic out and re-hem the sleeves.