I believe you have two very different options for towers:
1) Aftermarket tower; most are adjustable in width (I would tell you to start with a Roswell tower, as they would have been my choice if I hadn't gone with a factory tower) and can be adjusted properly to fit your specific boat contours. If you go this way, pay very close attention to the installation instructions as there are many bolts that require loctite, and many others that have to be free to turn.
2) An OEM replacement tower (likely manufactured by XTP). I bought one for the 180SP I had previously, and even though it was more money, it was rock-solid and a guaranteed fit.
Plan to spend at least $1500 on an adjustable and up to $2500-3000 on a factory tower, including shipping costs which were pretty expensive.
FYI, there was never a factory tower for that model year. As mentioned, though, beam doesn't really mean much. If you're doing it yourself, or having something made custom/one-off, you'll need to take measurements at the MOUNTING locations. Otherwise, find a tower company that has the template for your boat. Google will be your friend, here.
My BR 210 is a 1998, but the specs and overall shape appear very similar to your 2000. I personally don't care too much for the look of my Monster Tower MTI as it doesn't really flow with the lines at certain angles, but this is what was installed at the dealership back in 1998 (According to a former Marine Max mechanic who told me he's installed many on the same boat in his day). It was one of the few towers that would accommodate the factory bimini top at the time so that might be something you want to consider. Aside from that, its actually a very strong and solid tower and I've heard their customer service is second to none.
I used to know where there was a tower configurator where you could place a tower on a picture of your boat to see how it looked, but I can't find it now.