Well.... See what they offer you if you keep the car. I'm not sure which is more work... Engine swap or just fixing your car.
Take closer look at it and take inventory on what you need. See if it is fixable at all. I can tell you from my brief search for a silver fender an hood, there are lots of E39 used parts available in the Toronto area.
Used M-tec bumper is a challenge, but I think you already know where to find those.
E39 528i Touring - Unicorn Package (5 Spd M)
E39 M5 - for Sunny Days