With two boys, longer will be better. My family loves our bunkhouse. Yes, there are features we wish we had but that’s ok. There are lots of features out there you probably don’t need or wouldn’t use. It’s one of those things you won’t know until you do it. Don’t get sucked into the hype about this, that, or the other.
I’m not convinced that renting is all that’s it’s cracked up to be. Here’s why: there’s a big learning curve to camping. As you move up the curve, you get more comfortable. As you get more comfortable, you have more fun. If you judge camping by one trip to one park in a camper you aren’t familiar with, you probably aren’t going to have a realistic view of things.
The biggest risk you face here is financial. Mitigate that risk by buying used, ideally with cash. Look at a lot of units and when you see a possible winner, spend an hour with your boys in it. Lay down in the beds, pretend to use the John and shower, pretend to watch tv...all that stuff. Inspect closely and negotiate diligently.
As for truck, look for postings from people with trucks like yours and from people with trucks you are considering. You minimize your financial risks by keeping the truck you have, but your Tahoe limits your choices. I don’t think you can go wrong buying a used F150 from a financial standpoint. You’re still limited on trailer size with a 150. The tough spot here is that if buy small to keep your Tahoe, you may wish you had gone bigger. If you buy a bigger trailer and a 150, you may find the 150 isn’t big enough. If you bite off on a 250 or 350 so you can get a bigger trailer, you may not want to keep that big of a truck if you decide camping isn’t for you. There’s a lot of stuff posted about truck size on the site and I encourage you to avoid most of those threads as most generally conclude you need a 350 duelly to tow a pop up camper. I’m being facetious but only slightly. ??. Focus on posts presented by people with the combination you are looking at. You have lots of options in the half ton class.