@Schoonerman Hey! Always nice to meet another 360 owner. Aftermarket options are limited to classicswede.co.uk - even some standard parts like the clutch release bearing have been discontinued and are no longer available (other than occasional New Old Stock (NOS) items).
The 360's are very unique cars and I love mine to death. If you can get past the lack of available parts, both standard and Aftermarket, and are willing to get some deep pocket extensions and grow a beard full of patience, these little buzz box's can be a hoot to own and drive.
The b200e, although its a great reliable motor, it didnt quite have the power I was craving. The turbo swap made the most sense to me, but I was also considering the 'r sport' kit for my b19e engine (twin carbs) and even a N/A 16 valve on a b230 block. But again, the b230 turbo was the most logical path for me to take (although, I dare not think of how much I've spent so far, and mine is far from perfect.).
Volvo300mania.com is a great place to find information about these 360's, as the forum is dedicated to 300 series volvo's. It's a bit of a nightmare to use their search function, but there's plenty of very helpful threads, depending on which path you Choose to take.
I've covered a lot of information for doing a b230 turbo swap on this thread:
https://ozvolvo.org/discussion/10106/volvo-360-b230-turbo-swap#latest
Always happy to talk and/or answer any question you have. @pigdog @Raebird @Laurie are all 360 owners. Laurie has quite the collection and has recently started a thread for just 360's:
https://ozvolvo.org/discussion/10961/360-all-matters-360-glt/p1
This forum is great and full of like-minded individuals who are more than happy to help out where they can. I owe a lot to some members on here who have helped me along the way, and there have been many.
Welcome home.