I built mine out of black walnut just because I have a good supply of right from the tree that a good friend in Minnesota cut down and had milled. Problem it is pretty heavy to carry in and out of the house. You might want to use a white pine or spruce just because of weight. Oak or hickory will work just fine and look great. If you want it to look really nice, go with the hickory. If you put a clear finish on it, out side only, it will end up with a wide range of colors and really nice grain patterns.
If you are an experienced wood worker, search "Watch me build an observation hive" on this board for a detailed lesson on how to build a really nice table mounted OB hive.
Good Luck. Be sure to post some pictures.