My first order. What to do?

Many years back we ordered from MurrayMcMurray. I have decided I am going to give meat birds a try again and am set on 15 Pioneers https://www.mcmurrayhatchery.com/pioneer.html. This decision was based on them being the only ones with a good outlook for being in stock when I order for the Oct 27th hatch + I will keep a couple of the hens for eggs and I think they are pretty. Rest go to freezer camp @ 12 weeks. I have a place for them to get feathered out then into the run with the other 2 we have. Other 2 arent laying to well so they may not be here for the arrival of the chicks anyway. I'm still looking for a feed supplier that can give me starter / grower in one bag. The simpler the better for me. This will be supplemented with yogurt and veggies occasionally, scratch when they are big enough.

My first concern... Is mcmurray decent? This is going to be my first meat project on my own and I want to get the best I can. Looking for first hand experiences with them, else with other hatcheries that may be better.

Second, is a starter / grower mix a good thing or should I do them separately, and if separately then how long do I feed the starter?