A boosted LS/vtak will make more HP but about the same tourqe as a boosted LS. The LS/vtak will cost more than the LS because of the Vtak head, the external vtak oil line, and the vtak ECU. You could always just add a vtak head to a boosted LS and gain some HP since, the exhaust manifolds are the same. If money is not a problem then go ahead and do the boosted LS/vtak. If you want to conserve money then just boost a LS. Either way if you don't cut corners and rig shit, i.e. oil lines, tune, etc, they will both be quite reliable.