There's no reason why you couldn't decide on an assembly to get started on (tanks, ailerons, flaps), study the drawings and make a list of all the parts you'd need, get those ordered, and get to work. Then, when you order your wing kit, delete from the order all the parts you previously purchased. You'd probably spend a little more on shipping in the long run.
RV-9A Kit #90217 Sold;
Scrounging RV-3 parts
RV-9 Tail Kit #91415 on Deck
I love it when a plane comes together!