I'd take the 8'8 SP25 and add some Quobba Mixed Thruster set fins to it.... but I'd also recommend buying a large center Quobba if it gets juicy. Plus your best Quad set of regular fins if you have some.
Sean rides it as a Thruster.
The SP25 is primarily designed for small to medium average waves, but will easily handle some good waves.
I have had good reports from people who used the SP25 in solid surf and loved it.
It may not cling to the face of a super hollow barrel, but for most surfing that we do on SUP, it should be awesome.
I have both boards you mentioned
I love my 8'10 Placid, but I would take my 8'8 SP25 on that trip because it is noticeably faster than the Placid.
Sean Poynter rides it in some pretty solid waves and does some serious hacks with it.
This wave isn't big.... but it shows how he designed it to ride.