all d series are just about the same. just like z6 and y8 are same shit except different obd and cams. jdm d15b and d16z6 are same shit except one is 1.5l and other is 1.6l.
d15z1 with z6 head is same shit as a d16z6.
i would say jdm d15b since its 1.5l ( thicker walls? ) and its vtec, also has the best stock d series cam.

useful links
http://www.d-series.org/forums/.

d series overall are great to play with. the only weakness they have are thin rods