As far as all mediums verses mixed deeps and mediums, Just from my experience, I can see more advantages with using all mediums. When I bought my first nucs, the beek only had 5 frame deeps so I started with mixed boxes. Call me a glutton for punishment, I even have some shallows that I use. I actually like them as much or maybe more than the mediums. It would be MUCH easier to use the same size box for your bees. If it is deeps or mediums or shallows, that is your choice. The advantage with mediums is that they are the most common size for someone to use if they are using only one size. I am the type of person that wants to try everything for myself and make my own choice. I make most of my equipment so I'm not limited.
Foundation is a matter of personal preference. When I started 3 years ago, I was going to go completely foundationless. The bees changed my mind after cross combing half of a super between inspections. I now have mostly wax foundation, some foundationless and this year I bought some plastic foundation to try. I think that most beeks will agree that the bees draw foundationless frames the fastest(the most natural). Although they will work with wax or plastic too. My advise would be to use wax foundation to start with. If you want to try foundationless or the plastic, try it a little at a time after you are more comfortable with your bees.
No matter how much reading that you do, There is no better teacher than your bees. If you need more to read, Michael Bush's website was in valueable to me starting out.