I had D17a2 installed in my Civic 2002 Vti, it was alot better then D15 interms of Power and high end torque. it has more bhp and you can rev it with some heart. and rely on heavy tuning aswell.
I dont know about earlier engine in Civic 2000 or 1995. but in my experience If you have 7th gen civic then always try D17a1 (for Exi , this does not have VTEC) and D17a2 for Vti .
I had Stage 1 done on my D17a2 (headers, pipings and Intake and Plugs) i used to beat beat 1.8 Civic and Corolla 1.8 .. marginally. (means it was equal having 1.8 civic or corolla)