it doesn't much matter which reliable tx you get, all will work just fine. what will matter with little birds is weight, so a small rx and servos should be used.
also do consider that if you're going to build/buy more r/c vehicles, or increase your flight stable, particularly if you buy some that come with an rx, radio protocol can be a issue. a multi-protocol radio might be a consideration, and if so (or even if not!) i recommend the
jumper t8sg tx. it's cheap, to boot! i have two!