A lightweight BBU.
Everyone says barrel and bucking, reality most of the time even if it's to be used as a primary is you won't be reaching out 50M with it. Most are going to be 20-25M max so barrel and bucking are more "nice to haves" as the TM stuff is pretty decent.
Lightweight BBU though, will reduce the impact stress on the slide (making it last longer) and will make it significantly more snappy and likely a bit better gas efficiency as well as it'll move that bit easier.
Other than that, a good strip and clean now and again and it'll serve you very well.