I highly recommend Dan Junker and his boat, Relentless out of Falmouth. You can reach him at (508) 458-9445. According to him, the fish will be there 'till Thanksgiving, although the weather will get worse. I suspect he'd be glad to book you for a day trip, which runs $800. He's a top notch skipper who specialized his boat for giant tuna, but will also do 'light stand-up' for small tuna, and yes, even bass and bluefish trips. Larry and I chartered with him twice, were very impressed and learned a lot each time.
Initially, I found him pretty set in his ways, but after watching the boat in action as we played our large fish, it's clear that every line, cleat and gizmo on his boat is in exactly the large place to do the job, and, yes, there is reason for the heavy gear he advocates. Be warned, he's not going to be too supportive of your waving a 9 wt at giant tuna.
Also, he's pretty hyped up just as the fish hits, but there are dozens of things to be done within seconds, and they have to be done right. Just let him do his job.
Overall, I can't recommend him too highly. I think your chances of scoring on a huge fish are excellent with him.