Get the biggest one you can afford Mojo. You can switch plates around if needed but to do a big amount at once required a LOT of pressure. The bigger the plates = less pressure.
So if you want big plates you need big pressure.
30 ton is very good and more than most use. I use 20 ton and can do an ounce easily at once.......not 2 though.
What you want is 10 x 5 or 4 plates but you need BIG pressure to over come the size of the area of the plates....you see? That would press big time amount at once. Big amounts are trickier.