here is a full build thread on LS/Vtec.. although this isnt what you will be doing, this give a lot of great information when it comes to building a reliable motor.

How to build a "reliable" lsvtec/b20vtec - Honda-Tech

Now.. like I said before.. it depends on what kinda money you feel like spending on your car. Once income tax gets here.. this will be my next project. =]

** EDIT **
You dont need a new block or anything like that unless there is damage to the block, (i.e. cracks, holes, ect.) just clean it and make it all nice and shiney. lol the best thing to use is brakleen (?sp) get it at advanced.. its brake parts cleaner but that shit works wonders.. just srpay it on.. let it sit a few minutes to work into the crud and shit then spray some more and whallaaahhh all clean.