I've just taken a 998 auto out to replace it with a 1098 manual. But from my auto experience. Cheap mineral 20W/50 oil works best. Anything else is too thin, and also finds its way out the bottom onto the road a lot more easily. The gearbox was designed to run on 1960s oils. It will only run worse on the modern stuff as it will interfere with the bands in the gearbox. I Always fit NGK BP6Es to my Minis, but for some reason my old auto was happier on BP5Es but I think that was just a quirk of that particular engine.
If anyone wants an auto subframe i've still got it sitting in the garage. I've heard they're good for fitting turbo engines due to the different engine mounting position.