Hard to say which is "best", but it's going to be hard to justify the cost of that LS-1 package I would think. The $3500 in labor you traded for the BBC has some lower "cost" to you - your break-even cost compared to your billing rate, but then you traded something of value for the 350/350 combo. The 350/350 will be easier to finish, and offers the most opportunity for more power/torque down the road without too much added cost; where the 454/400 is going to require more deep pocket work to build. From a selling standpoint (return on investment) you'd probably do best by adding a little "bling" to the 350 for eye appeal, and advertise the potential.