I bought two of the Saturn/Playstation Total Control converters. I only have the 3D controller for my Saturn, so I unfortunately have to use two of those Ryu Street Fighter Controllers for the PS2 with my Dreamcast for playing fighters. Not the best option, but better than using the Dreamcast pad. On the other hand, I DO have the solution for the converter box not reading VMUs. I just plug a stock DC pad into the fourth controller port, and plug both my VMU and 4x Memory Card into it. Then just select that from the menu as your save/load point. Much more reliable, and it works too.
If Saturn controllers were easier to come by, I'd buy a whole bunch of them to last me a long time. But they are scarce as hell.