Definitely get a new paper gasket or two to make sure you re-seal it as best as possible. The big o-rings should be fine to reuse. Same goes for the chain cover gaskets. Chain tensioner o-rings might be wise to grab another. Sometimes taking the cover off can disturb that.
I would just do the cam cover plate on the flat surface. Use 600 or 800 grit to save yourself some time. No need for it to be super fine surface like 1000 or 1500. But feel free to make the surface as smooth as you like. Color it with a permanent marker so you can see your progress.
I will be interested to see how your gasket looks when you get the cover off. I think it's more the lack of contact area between the cover and the cam housing, than it is the actual gasket position itself. I recall my leak being a strong one that ran down the case, right onto my exhaust (my exhaust was a set of crazy expensive custom headers from MODE that I inherited with the car and the exhaust was plumbed toward the inside of the engine) and made for a big mess. Definitely not a leak that can be ignored, unfortunately. Not to mention nobody likes ANY leaks after their hard work!
Another gasket sealing question
The picture below is pre-rebuild, just to show the routing of the exhaust. I will be honest that the leakiness of the engine was the primary reason for the FULL rebuild after my first failure, which turned out to be a chain tension problem (seized idler arm) and there's no way an anal retentive nutjob like me could tolerate leaving all that filth on there......
