Hi
It depends on how accuarte you want your 2V to be. A linear regulator (LM317) etc will give you an output voltage that can drive a decent amount of current, but the output will not be accurate to ppm.
If you want something stonkingly accurate, go for a voltage reference. Look at Maxim or TI for a 2.048V reference. This should be good enough for your applications. However, references cannot drive a great deal of output current, so you might have to put an op amp follower on the ouput if you want more welly out of it