I'm not from Philadelphia or in Philadelphia so I guess I shouldn't be asking how to make a quality PHILLY steak & onion sandwich necessarily.

I guess my questions are...
1) First and foremost, what is the tastiest and most tender-est cut of steak that you would recommend to use when making these at home? I'm a "filet guy" in steak terms. I prefer it to any other cut I know of just solely because I'm a tenderness kinda guy

2) What specifically would I want to look for in terms of the label at the supermarket in regards to this ideal cut of steak, if there is one? Or should I not even be looking for this cut in a mere "supermarket"?
3) What is the general best way (in your opinion) to slice, cook and/or season these steak fragments once I get going?
4) How about the onions (the other part I really love)? Could I sautee them? Carmelize them? Just cook them raw along with the steak pieces?
5) What are your feelings and recommendations about the cheese? I like a "dollop" of cheese on items such as these but not TONS of it. I prefer to enjoy more of the steak and onion than the cheese in terms of the proportions. But I'm definitely open to hearing what others recommend to use and or what types. I thought I read somewhere before that, interestingly enough, the traditional philly cheese steak (that the Philadelphians make) don't use real melted cheese on most of these sandwiches but rather just a cheese "sauce"?
Having said all that, I'm actually not looking to stay strictly Philadelphia-authentic with these. Just looking for some tips on how to make a tender, tasty, quality one at home first and foremost. As we all know, the toppings and or seasonings could probably be embellished or preferred in a million different ways...
P.S. Oh wow! Just as I was finishing up typing this, a "philly steak" segment just came on the food network here!

Thanks for any thoughts you may have though! I appreciate it!
Jeff