Just use 100nF caps, I think they're 0603 size. That's what we used on the other chip.

edit: You'll need a way of configuring the extra RAM before the unit actually uses any of it. The central, ISTR, works the same way as the carplayer did in that 0xe000 has the "run linux" code in there, which is run direct from flash and hence you can munge the enables for the second SDRAM bank in there. The sequence is more involved than the carplayer's due to it being SDRAM as opposed to FPM; download the SA1110 datasheet for more info.

The existing SDRAM init code will be in the main loader, at 0x0 in flash, but I don't recommend you attempt to modify and reflash this as if you get it wrong you will need to either:

a) Desolder/reprogram/resolder the flash TSOP
b) FInd that old SA1110 intel reflasher program that bit-bangs a parallel port JTAG (DLC5 cable) in order to drive the boundary scan of the CPU to reprogram the attached intel flash.

Doing it at 0xe000 means you can reflash over serial if it doesn't work.

Good luck! 32MB should pretty much make the central fly with big disks..

Hugo