Like CaliCamper said, the 2.7 is a freaking rocket and in Sport mode it's even more fun. Does not act or feel like a truck. I had so much fun in my 2.7. and I did everything from commuting every day, towing a 21 foot ski boat, and hauling 1.5 yards of rocks. My last truck was a lease and I didn't like the fact I was getting a 2.7 over the other options at first but it really was nice and I came to love than engine. Plus, either engine will net you the 10 Speed trans which is fantastic (depending on year) I love my new 5.0 but only have the 6 speed and miss the 10 dearly.
For what you're describing, the 2.7 or the 3.5 will be perfect for you. The 2.7 should be easier to find as they made more of them and will be priced somewhat lower in the aftermarket.
I'm a biased ford guy but I have driven the Ram 1500 and didn't think much of it.