The D16Z you're thinking of is the D16Z6 in our reference section. Go look it up. It came stock in the 92-95 USDM Civic Si and EX, and has 125hp at the crank from the factory. If you put one of those into your HF, you'll have to wire for VTEC, then convert to OBD1 to run the P28 ECU (matches the D16Z6) or stay OBD0 and run an rpm switch or VAFC (or something else) to activate your VTEC.
Overall, the ZC will be easier to put into your HF since you won't need to wire for VTEC or deal with the hassle of possibly converting to OBD1- and it generally has higher stock power numbers. You don't get VTEC, but you do get one of the strongest bottom ends that was ever available in a D block from the factory. It's stronger than the D16Z6.
Since you're trying to stay on a tight budget, I'll just assume that you're not going to want to dig inside the engine and play around. If you want to boost your swap, the DOHC ZC is probably the best engine to get. You get a higher stock power rating, you don't have to deal with VTEC, you have a better crank girdle and better bottom end lubrication- and you also have two cams that you can adjust to maximize power with under boost. With the single cam, you can't adjust your intake/exhaust overlap.
If you want to keep feeding money into the engine, the D16Z6 will be a better option for you. Since it was available in the States (and in pretty large quantity), it has a pretty healthy aftermarket support structure. You can get custom pistons, rods, cams etc for it pretty easily, while you can't really do the same for the ZC. If you want to build up the bottom end on a budget, you can use LS (B18B) rods and modify them to fit. You have to shave one of the ends (I forget which one) of the rod, and you have to notch the block to clear the larger rod. If you're willing to put more money into it, you can get aftermarket rods/pistons for either block- but that will probably run you around $700 or more, depending on what you get.
As for time to put it into the car- everything physically bolts right up on both engines. You might have to screw with the wiring some depending on which block you install, but the mounts match up.
One note- if you use the D16Z6, you can't use the D16Z6 transmission. The clutch is hydraulically activated, while your 89 HF chassis uses a cable clutch. You'll have to either use your stock transmission (really really tall gearing) or find another 89-91 D series transmission.
I don't know why I just typed this all for you... I guess I just felt like it. Food coma does weird things to you.
