Just be sure to get the correct size aluminum pot to convert into the kettle. I'd also use a stainless (3-piece) ball valve and get a dip tube to work with it. You can go with the 1/2" NPT to 1/2" compression fitting, a few washers, silicone washers/o-rings, and dip tube all from Bargain Fittings. Should be about $45 plus shipping. The dip tube will help you to extract more wort without having to tip the kettle to extract. Also, use 1/2" ball valves, not 3/8" for this. If you want to go larger, you can, but make sure you can get everything in the larger size (1/2" NPT is far more common).
BTW, I've designed, and make, my own sight tubes/glasses. All stainless fittings and borosilicate glass tubes for it. No worries about temperatures this way (unlike with the polycarbonate tubes).