You work for a U.S. company and have been asked to set up a contract

Assignment:You work for a U.S. company and have been asked to set up a contract with a supplier in England. You anticipate about $1M in transactions over a 12 month period. Would you try to negotiate a spot currency rate or a forward currency rate? If the latter what maturity date would you use? Please provide justification for your selection (Brexit references encouraged).