well the H is alot more modifying... but the D16 will wire right up with the D16 harness and then just replace the computer with one from a Z6 that way your vtec works i think its a p28 but dont quote me...... and i believe your golden... but with the H you got alot more modifying and alot of adaptors and such to wire up....

just depends how much more HP you want and the ease of swap..

more HP but more expensive and harder the H
ease of swap and cheap the Z6


i prefer my Z6 myself got enough kick for me and gets good milage.