I would think that keeping the engine system all the same brand and close year match would result in a more trouble-free mating of the components.
However, if the bike already had the components mated successfully, it would come down to the cost and available play money.
author "Old Bikes"
too many bikes to list, including:
JPN, 952 Prototype, MkIII Interstate, Combat Dunstall, VR880 SS, Triton