I've always had an LS\VTEC money\time build guide in my head.
Buy a B16A swap, install it.
Buy a B18A\B block, build it on the side. Your car is still running, no down time here.
Once the block is prepared, buy anything else necessary you can imagine yourself needing for a block swap weekend (I actually had one written out, not about to post it in it's lengthitude.... YES that's a word.. I made it, so it's real).
Swap the block and enjoy an LS\VTEC without the hassle of down time or rushing the bottom end.
Buying the B16A first guarantees you the availability of difficult to find parts. The B16A parts are rarer to find away from a full swap, and though they seem to be all over the place, they get expensive once they are separated from the engine.
-The trannies are around $4-600, LS gears are okay.. but LONG
-Great starting ECU, even functional enough to drive your new motor to the dyno.
-Purchasing a liberated head is dangerous. I've seen a lot of mishandling with cylinder heads go on leading to damaged gasket surfaces, blown gaskets, improper function and worse. Gasket mating surfaces are crucial to keep in excellent condition. We often don't think about it when installing something like a water pump because it's easy to handle and goes straight to where it's installed. The head is heavier, more difficult to maneuver\work with (isometrics are tough), and creates this "solid" feeling, thus creating "durably inspired actions" by the handler (who is usually uneducated about engines). Basically, what I'm saying is I watch people sit bare bottomed heads where they DON'T BELONG all of the time. Never trust the person before you. An un-liberated head has a greater chance of being flatter to the CC bores.
The deal you are getting on the B18A is basically too good to pass up, so if you get it and choose LS\VTEC, you'll have to deal with a LOT of piecing together. It's easier to find an LS block for cheap than it is to find a VTEC head (remember, there's a lot of shit on the head, intake, TB, MAP, TPS, Dizzy, rail, inj., countless items, and most heads are incomplete), better trans, ECU, etc... In fact, you may want to consider buying a B16A swap and then adding an LS block. The additional torque to be had by choosing the B18A is marginal and shouldn't be considered a selling point. Compare two of the same cars, with a B16A and a B18A, equal drivers\conditions\variables, the B16A wins more races and more KINDS of races, even POSSIBLY a q\m, but certainly not the eighth mile.
You may want to buy the B18A anyway, for the price, you can make a lot of power just in spending the difference of a B16A swap. I thoroughly recommend the use of a VTEC head on very applicable application, as well as some route of forced induction.