[asid61]

I would pick up a couple AM-9015s for use on manipulators, and another battery; they run out of charge faster than you'd expect. I don't know what rookies teams usually get in the KOP.
A PG71 with encoder could also be handy. Some shaft collars could come in handy.
If you opted out of the KOP chassis, it's going to be tricky to build your own. What are your facilities? Is there a nearby team mentoring you? What is your budget for the coming year? Some things are better deals than others.