My older daughter has a DS Lite with an Edge cart. Everything works fine - there are basically no problems. I am getting my younger daughter a DSi this Christmas. Should I get her an iEdge to keep things (somewhat) consistent? Or should I get her something that supports Wood like an R4 cart? I admit, I don't know exactly what Wood is yet or if I really need it. The girls just play commercial games and watch an occasional movie so maximum compatibility and future proofing are my main concerns. No real need for in-game saves and guides or GBA abilities. Thanks.