Any suggestions on what I should consider? I'm looking for
decent-to-good quality (I'm not knowledgeable or trained enough to
make use of better).

A google search let me find out what kind of knife should be used, and
(of course) all the selling sites say theirs is the best, most-used,
most liked, etc.

I'll mostly (at least initially) be slicing maguro, hamachi, and toro.

(I can give a very favorable review to catalinaop.com.)

Thanks,

Seth