Have to agree with whats been said. Keep it simple on your first tank. Upgrade as things break or the want to improve reliability if need be.
Will also make for a fun experience with your son to install any of these down the road together. You'll learn what makes these things tick and within a year or 2 I'm guessing your motor pool will expand. Not sure how old your son is but this is a great hobby for little ones to get involved. Whether it's a 3 yr old helping you glue a small detail part, to a 6yr old helping to change out gearboxes, to a 14 yr old crushing all the old farts in IR battle (6yr olds do that as well!). Keep it fun and don't be discouraged by mechanical failures, they are bound to happen and part of the fun of the hobby is wrenching on these suckers.