If you want a simple kit check out any of the Austin Hombrew IPA kits. I almost always have one on tap throughout the year. The AHS anniversary IPA is great and so is the budget IPA kit, that I believe uses greenbelt Wyeast that I really like.
If I can offer a single piece of advice...
I have had good luck with the Austin Clone kits, and Austin Homebrewer in general. I have not made their Fat Tire clone, but I did make Northern Brewer's flat tire clone, and it was very good. You probably can't go wrong between Austin and NB.
It's been my experience that NB, and many other Homebrew shops underestimate the time needed. I have good pipeline going so most of beers are 10 to 16 weeks along when I tap them. I think this is also one of the reasons that I have not encountered "extract twang" when I was doing extracts.
It's a hobby, so I will spend a few bucks on it, I don't think I'm saving any money but it has been years since I last calculated. When I compare brewing with my weekly golf habit, it is my cheapest hobby :). I enjoy both so the expense is a nonissue for me.
I use DME to boost the ABV. I have used the Austin boosters in the past with no ill effects, but I always have DME laying around so I usually use that.
I believe you have what is called a static relief valve that is suppose to release at 60 psi. If it is leaking it probably needs to be replaced. I'm on my phone so I can't link the page, but search homebrewtalk for static relief valve, there are a few how to guides.
https://www.homebrewtalk.com/f37/late-addition-hop-utilization-188394/
Interesting thread that addresses hop utilization, including Palmer mentioning that he was incorrect in his book; he discusses the topic at about the 37 min mark:
March 20th 2008 recording...
Austin Homebrew Supply has a great anniversary IPA that they run at a sale price from time to time. My SG was 1.068 and it fermented out to a FG of 1.014.
Before I moved outside with a burner I did split boils on the stove all the time, including all grain batches.
I wouldn't worry too much about not getting a rolling boil. I'm certain your beer will be fine.