ARES is a great and complete set of fantasy rules for 15mm or 28mm. One purchase gets you everything, and there are additional rules, errata, and expansions available free from the publisher's website.
If you want a set of fantasy or historical rules that has more crunch and a lot less randomness than Song of Blades and Heroes, this is what you want! Uses several sizes of dice and requires some mental arithmetic, so it's a good basis for building kid's number skills.
[5 of 5 Stars!]