i believe the y8 engine is the single cam VTEC engine, and the y7 is the non-vtec engine. the y7 is only rated at 106hp or something like that, and the y8 is around 120-ish, stock. the y8 with intake-header-exhaust would probably be the same as a pro5 with only intake and exhaust. while the civic doesn't really have a high torque rating, they make up for it in lightness and rpm's. the y8 will run up to 7500? before the revlimiter kicks it, and the civic run a couple hundred puond lighter that the pro5.
if both were stock, i'd give the pro5 the nod, but not by much. with the mods, my money's on the civic. sorry.
fyi - my wife's car is a civic lx with the y7 engine. it has an exhaust, and thats it, and it feels more sprightly than my car with intake-header-exhaust. (i don't think its faster, but light wieght ownz joo!!!)