the wrap i think you need is one that measures 4.6m. if you are a size 12 or smaller, you can do all the carries with this length. for the summer, a cotton gauze wrap from calin bleu will do the trick. don't worry too much about overheating. in hot countries people wrap too.
also if you look at the didymos website, the wrap i recommend for putting on sling and then inserting a baby is the 'front carry (variation)'. it looks complicated but if you follow the steps, it is idiot proof.
i don't have time at the moment to look for a video of it, but maybe if you go to youtube and type in what i wrote in brackets, you may get a video?