From the RECURVE chapter in TBBII...."Prehaps the best trade-off between speed and accuracy is a recurve of 60" to 64", measured before the tips are bent(this is for a 28" draw)".
There is a lot of good info in this chapter about recurves and the previous chapter on bending wood.
Also, check out Dean Torges video "Hunting The Bamboo Backed Bow".