The general rule of thumb for putting together a mule deer/elk system is start with boots and pack. There are several great options for each and in both cases, the one that fits your body the best is probably going to be best for you. That said I did my first mule deer and elk hunts only with what I used for hunting deer at home. Got some experience and then set about buying the gear specifically for hunting in big mountains, starting with boots and pack, then sleep system. I'm not hunting normally in areas suitable for doing much glassing so good optics are not on my list but they would be high if I hunted more open country.