It's my opinion that LS VTec is only a good idea if you already have an LS block or a Vtec head. It ends up costing quite a bit and getting very involved if you are starting from scratch. Honda made an engine very similar to LS VTec, it's called GSR. I know the numbers aren't the same, but the idea is similar. A 1.8L block with a VTec head.
Though, i think you should do whatever you want, i know people who have done LS VTec just to say they could.