I was going to vote for the CH DT225...until I saw that it was for the PS/2 version.
That was an instant deal-killer, because the one reason to own a DT225 with other competing models like the L-Trac around is for Control Manager support so that you can boast about having the most programmable trackball in the world and have the software to back it up. Needless to say, the Control Manager only works with their USB peripherals.
But if you can get a USB DT225, that paired with a Fighterstick makes a far better combo than a Mad Catz Panther XL, that's for sure.
I didn't know Sanwa made trackballs (or anything other than arcade joysticks and pushbuttons, really), but those don't look like anything I'd see in an arcade cabinet. Come to think of it, who made the huge 3" trackballs you'd see in those old Missile Command, Millipede, Marble Madness, etc. machines? One of those, flanked by three to five arcade pushbuttons and wrapped up in a nice wood enclosure akin to a real arcade cabinet, would be just the ticket...