The big question ... have you driven either vehicle or any 4th gen v6/v8 for that matter? I only ask because you should probably hold off deciding until you've had experience with both so that you can make an educated decision.
When I was looking, I wanted the v6 but test drove the v8 to see the difference. I was more than happy with the power of the v6 and preferred the fuel economy which I would notice every day versus the extra power that I would rarely if ever need. I don't own a boat, I don't tow a heavy trailer, I don't need to overtake anyone on the highway any faster than I already can. The v6 has been great for me but then again those are my needs.
Colorado is going to be an inflated market for SUV's because everyone thinks they need them out there. There's a lot of offroad/outdoors/camping/cycling/kayaking etc immediately nearby so everyone seems to drive a Subaru, 4runner, jeep or xterra. The other thing is that 4runners are one of the last remaining body on frame SUVs really capable of going off road while also getting reasonable gas mileage and having a very long lasting motor. If you're absolutely sold on the Sport models then you are going to pay a little more than you would an SR5 which has basically all the same features minus the wheels and cosmetic hood scoop. I've seen equivalent SR5's for $14k fairly often around here (chicago) so maybe just hold out and the right one will come along, or bargain a little harder for the one you want. While 4runners hold their value, a $15-20k 7 year old vehicle with close to 100k miles isn't really going to fly out the door. Go in low and see what happens. The least they will do is say no. The best that will happen is they lower the price.