Morrowind Sweps is most definitely the best Sweps available, and are in general very fitting for our roleplaying needs. I don't think anyone would argue with having them. You can grab them easily off of workshop. The old Wizard models were recently updated for Gmod 13, so those might be nice to have.
I remember roughly how to swap heads with PAC, it isn't terrible, but it requires some messing around with your entity model and an added model with bonemerge.
I'd recommend the Ineu series of maps for use in events. Ineu Pass 1, Ineu Valley 1, Ineu Valley 2. Ineu Valley 2 is particularly impressive, but that's just my opinion.
M9K has a few specialty weapons we could make use of, some explosives for magical effects perhaps. I know there's a mod for the Battlefield compound bow.