Noise performance of various TL431 flavours...

Motorola TL431

Texas Instruments TL431

NXP (Philips) TL431

National, Fairchild and ST also manufacture these but noise voltage is unspecified.

Noise performance of various SHUNT regulators...

Motorola LM285

Motorola NCP100

Motorola NCV1009

Noise performance of various SERIES regulators...

LT1761

LT1764

Low noise low dropout 3 amps regulator. There is a pre-set variant at 3.3V which would be perfect for the Suzaku board. Linear makes some nice low noise (still a lot higher than a TL431) high current regulators, which would be good to power general logic or opamps.

LT3010

MAX6220

Good performance, but expensive.

MAX6350

Good performance, but expensive.