Tim,
Do you know what length oars and bowsprit you are looking for?
The standard oars for a BR20 are a bit less than 9ft long but, depending on which part of the boat you are rowing from, more efficient oars are quite a bit longer.
There are two choices for the bowsprit - a wooden one fixed to the foredeck, the end held down by a bobstay, as on a BRe; or a carbon fibre pole run out through a hole on the starboard side of the bow. Your asymmetric luff may then need to reflect the length of your sprit. Earlier BR20’s had very long carbon fibre poles as sprits and I think it was decided that they were a bit too long, so were shortened on more recent boats.