An LS/VTEC can be reliable, but it will take a bit of work and will end up costing you about the same as a B18C1 would in the long run. It's not simply a process of just bolting a VTEC head onto a non-VTEC block. You also need to change the water pump, timing belt and oil pump for VTEC versions and also installing a VTEC block girdle (which requires a lot of B18C1 parts or some machining to make it fit) and other parts is highly recommended. If you also don't have a more aggressively geared VTEC tranny, your really going to be hurting performance.

As for head works, the skys the limit on how much you can spend, but a good set of cams (skunk2 or CTR/ITR's) along with an upgraded valvetrain is probably going to set you back around $1000. A good valvejob and some port matching will also be around $800-$1000 but you would see solid performace gains from either. Seeya.