Plywood should be fine, if thick enough (1/4" certainly isn’t enough, 1/2" should be okay, 3/4" ought to be fine).
That said, mass is good, and helps dampen vibrations, so if the butcher block is in the budget, I’d get that — the much smaller table I use for my 4x2 has such a top:
Some folks have complained of racking, so diagonals where appropriate are a good idea, but I’d probably get lengths of aluminum bar (and matching or contrasting spray paint).