do you have the full setup for the 94 (engine, tranny, harness, ECU) if you do then you should be able to put that in in 1 day or less
simply pull the old engine and drop the new one in
reconect the hoses and plug the harness in at the shock towers
switch the ECU and your done
the 92 civics were all prewired for VTEC so you wont have to fuck with any of that
you will most likely still want to upgrade after that... then i would suggest a 1.8 DOHC... but if you have everything you need to drop the 94 D16Z6 in then why not do it