Your agi stones are pretty weak considering the VIP level you likely are. You'll be devastated by any true PvP player if you don't get a lot more speed. Speed is all that matters for pvp.
But if you still feel you need more silver and are willing to forgo winning as much in CSB then STR it is... I think that's short-sighted though. Maxing out agi stones asap is, imo, the best course so you keep your speed high. Especially since you're still stuck using Kisuke's extremely slow arse.
And if you were contemplating getting se xy yoru over quincy... the damage would likely be dramatically higher. When I added her in I went from 4-5 mil to 6-7 mil instantly replacing Kisuke. If that gives you any idea of the damage increase she gives over a basic tavern partner.