I would not consider option 1 unless you go with a big cam, headers, etc. But that wouldn't be a streetable, towing combo. The LQ4 engine in your truck already has LS6 heads (317 version), which flow enough stock to make over 500 HP.

Options 2 & 3 would certainly deliver the goods, but would cost you your first-born male child.

Option 4: cam & headers. For about a grand, you could pick up an easy 50-60 HP. For towing and good street manners I would suggest a cam in the 210/218 range, like the Vinci Ultra Torque at this link:

LS TRUCK CAMSHAFT

Option 5: supercharger. This would provide the most power in a streetable package, but won't be cheap. Kits like the Magnacharger or Kenne Bell go for $5K - $6K.