i'd consider selling it for not too much, and shipping within canada wouldn't be too bad (as opposed to bringing it in from the uk or us). mine has two bolt-in door bars on each side as well. works with the soft top, and you can remove any bars you don't want for day to day use.
I am deconfiguring my track Boxster today and have 2 OMP seats, BK bar and one-year old Schroth belts for sale. As you can see from the photos the OMP seats fit with custom made base plates that allow the sliders to be used and also the normal lap belts for non-track use. I don't know how tall you are but I am 5-10 and I have plenty of space below the BK bar. I would definitely fit the BK bar for the track. It only takes 10 minutes to install.
I am 5'11" but I have a tall torso compared to some. You have what I conceive to be the way to go. Could you let me know what you would like for the items you have and where you are? My wife wants to keep her heated passenger seat but I am interested. My direct email is fleet@camclarkmail.com . Thanks.