I’d say your options are:
Corsair C3
Pros: Higher level hook/hexen dropper/jolly roger, pistol shot is pretty decent in pve, really good in pvp. Aspana revolver (3 sockets for an off-hand weapon): https://tos.neet.tv/items/304104
Con: Rank 7 class for your rank 8 choice which means you may struggle in r8 content and maps as they are brutal. Also gotta hope rank 9 offers a follow up for corsair c3.
Murmillo
Pros: An actual r8 class with high base power skills. Boosts your pelt skills and synchro thrust which are also clonable by shinobi’s bunshin.
Cons: Gotta make use of weapon swap since some corsair skills are incompatible with shields. Also very expensive.
Doppel
Pros: Dov is still really good even with only a 50% increase, you also get cyclone which is a nice slash type skill which your toon lacks, r8 content is pretty cloth heavy.
Con: r6 class which means you’re still basically r7 dealing with r8 content.
If you don’t like any of these options, your best bet is to wait for r9 and make your decision from there.