If you are looking for RBI, go with Matsui.
If you are looking for HRs, go with Gibbons.
Otherwise, probably similar numbers with a slight edge in runs to Matsui.
Overall, I'd take Gibbons. The RBI and run difference isn't likely to be so great that it will trump the 10+ difference in HRs. And Gibbons has an outside shot at hitting more RBI than Matsui.
"The game has a cleanness. If you do a good job, the numbers say so. You don't have to ask anyone or play politics. You don't have to wait for the reviews." - Sandy Koufax