As mentioned earlier, if you can afford it (i.e. not become financially strapped and stressed out), go for it, although it sounds like you have reserves going into it already. On the flip side, isn't the TT you have about 5,500# dry?...correct me if I'm wrong. I recognize that it will weigh more than 5500# when fully loaded, but as long as you don't take the kitchen sink with you, your F-150 should be sufficient. We pull our Jayco 29L (5,500#)with an '05 F-150 SC with no problem. Based on your own words, it sounds like more of a want and not so much a need.
I just hate to see people go into allot of unnecessary debt, assuming you would be. As much as I would have LOVED to buy an F250 Diesel, the used F-150 SC that we purchased for $13K does just fine...it's certainly not the speediest thing on steeper inclines, but there's no rush.
2011 Jayco 29L w/Outside Kitchen
Reese Straight-Line WDH
2001 F250 Lariat 6.8L Crew w/Long Bed
Honda EU2000i Generator