how about just buy the civic you want to mod... drive it around for 6 months.. get the experience of the road, and then do your swap. in those 6 months, you can be saving money for that engine!
my parents put me in an 86 volvo 240DL before i *bought* my own civic. (yes i put the down payment and paid off my parents for the remaining cost). let me just say this: i drove the 86 volvo for 6 months... didnt have any accidents. when i started driving the civic, all sorts of fender benders happened (only 1 of 4 was actually my fault!) so it just goes to show that no matter what, you are gonna have some sort of accident in the first year or two of driving. the longer you go w/out modding your car, the more experience you will get to avoid those stupid ass accidents that *may* ruin your precious mods (ie body kit, fenders, rims, etc...). im glad i waited about a year before doing anything major like lowering my car and getting my kit/rims. just my 2c.