I have this exact setup (fittings from Bargain Fittings), but I do AG. In my opinion, the dip tube isn't necessarily a must, but could be an option if you like. I put a bazooka tube on mine, just for the hell of it. I like it because it filters out a good part of any gunk at the bottom when I drain. Depending on my final volume, if I need to get it all, I'll just tip the kettle on its side.
One thing to keep in mind with a dip tube, if youre throwing your hops directly in, you might clog the dip tube when you're draining. I use hop bags for all my additions, mainly for easy cleanup, but coupled with the bazooka tube, I think it makes for a smooth process.