i dont really keep up with h series engine swaps, but i'd say puttin a turbo h into a civic is just more trouble than it's worth. I've heard it can be a nightmare to get any h series into a civic. if your gonna go turbo, you might as well just go with what's been proven time and time again and find a b series engine to put in. you could use the money you'd save on any extra work you'd have to have done to get the h to fit and build up a stronger b. since your goin turbo, you'll be able to get as much power as you'd need.
if the car your buildin is for street use, a solid build b turbo will produce more power than you'll be able to run on the street anyways. also, i dont need people flamin me say that you can't have too much power on the street, cause i drove a buddies 500 hp supra, and believe me, drivin something with that much power on the street isn't easy. the car would have a tendency to take off like a rocket, and in traffic it can get tough to keep it under control. there is such a thing as too much power on the street, and anybody who thinks there isn't is definatly gonna wind up wrappin their baby around a tree.
all in all, i'd save yourself all the headaches of messin around with an h swap and just go with the trusty (and perfectly fitting) b series. but hey, if you do manage to get a working h turbo swap, more power to ya...
just my 2 cents, for whatever it's worth