The S52 was found in the E36 M3 from 1996-1999. The engine mounts should be the same which means it should be a direct bolt on. However it will depend on your transmission whether it will bolt up to your transmission. It bolts in fine but their will be small things you will need to make it work, including a new DME or have yours remapped. I'm not sure how the wiring harness will fit or if you'll have to replace it.
The engine is larger so their will be more weight. A suspension upgrade is always a good idea, especially if yours is still stock. However, before upgrading make sure your mainetence is up to date. Check all your suspension parts and bushings to make sure atheist in good order. A motor mount is cheap and when they go bad it causes an annoying vibration. Rear shock mounts are a common failure point on the E36 so make sure you get a really good set of those. The repair if they rip through the sheet metal is usually a couple thousand dollars. As for brakes the stock ones should be sufficient providing your not racing it or slamming on them all the time. I do hear that the Hawx pads and rotors are an excellent upgrade though. Haven't tried them myself but I'm going to do a brake job in the spring and will probably try them out then.
Replace what's worn and broken before spending money on fancy stuff is what I've been told.