Hi, you could consider the BCS system, went out for a test drive in their demo car and can confirm it did not drone at 80mph, I am booked in to have full TBE system with Valvetronic next week, my main thing was not too loud pottering about and no drone, but sporty on WOT.
APR systems are all pretty much priced identically wherever you buy I think, you might save £10 here of there, but its one of the most expensive out there.