Got to see my maintenance blokes this week. Short answer:
*Reserve an N-reg (if you wish)
*Export CofA from Brazil
*Owned by US citizen, corporation or trust fund
*US CofA & CofR
Longer answer from one of our PPRuNers who's website I stumbled across (the European stuff is irrelevant, but the US rego. stuff is worthwhile for your situation)
Moving to N-reg