I have the same motor in my Del Sol as you do in your DX Civic. First off, what is "blown" on your motor? Depending on what is wrong with your current d15b7 things can be had for a lot cheaper. If it's your head, then I would do a mini-me swap for sure. You can get everything you need for a lot cheaper than a motor swap, you would need the following:
d16z6 head $100
d16z6 dizzy $90
d16z6 VTEC solenoid $60
d16z6 intake manifold $50
d16z6 throttle body $40
p28 ECU $100
d16y8 3 layer head gasket $30
And if needed:
VTEC solenoid gasket $15
Intake manifold gasket $15
Total: $500
I priced everything on the higher side, if you look around you can get everything I listed above a lot cheaper. Or maybe go to a junk yard and pick up everything off of a wrecked car for dirt cheap. I was able to pick up everything listed above from a friend for $200. It's all about searching around on ebay, craigslist, and car related forums with classifieds.
Also the reason I listed the d16y8 head gasket is because one they are cheaper than the z6 head gasket, and two you can remove the center layer to make it a 2 layer. I like the "mini-me" swap over a complete motor swap because you will go from a 9.2:1 compression ratio with your stock d15b7 to 10.55:1 with the swap I listed above. Of course that means you will have to run higher than 87 octane fuel or else you risk detonation. But where as a stock z6/y8 is around 125hp with a proper mini-me swap your looking at over 130hp because of the higher compression.
And not to confuse you, you can get a y8 top end. You will just have to convert your OBD1 distributor connection to an OBD2 connection. Which is not that hard at all, and you will then have a newer motor, and the y8 on a b7 will give you 11:1 compression ratio which is not going to be noticeable from the .05 difference with the z6 head.
After you do the mini-me swap if you go that way I would start looking for an EX/Si transmission you can identify one of these as being an s20 B000 from the 92-95 Si/EX Civic or the s40 B000 from the 96-00 EX Civics. These transmissions are a bit stronger than the A000 versions, and they have shorter gears which will help you accelerate quicker. It's a great upgrade to do on our cars, and will be a huge improvement if doing a mini-me swap.
Also it would be a good idea while doing your mini-me swap to upgrade your exhaust manifold to a header, and your stock exhaust to a 2.25"-2.50" mandrel bent exhaust system. Throw in a K&N filter in your stock induction system and you should be pretty close to the 140hp range on that setup. And if you chip/socket your p28 ECU and find a hell of a tuner for CROME or Hondata I would not be surprised if you could reach over 140hp on this setup.
If I'm wrong about anything I've said please correct me so I'm not giving this young fellow false information. Thanks.