I also use La Sportiva Trango Alp GTX in winter or cooler months, and as you say, excellent boot, but for summer a bit too hot and quite heavy.
So for summer I bought Scarpa Marmolada Trek (they have them in Kibubi too), which are very light and despite waterproof membrane proven to breathe excellently. If you don't need boots for semi-automatic crampons and if the last fits you (both fit me super on the foot), then that's it
