I will not buy more Lee dies, and for one simple reason. When you break a de-capping pin you have to send the whole decap unit in for replacement, or go buy another. With my RCBS dies I buy pins five at a time and replace them myself in a minute or less.
When I was using military brass I was breaking pins regularly. Now it's only when something isn't lined up right, usually cause I'm going too fast. None the less, I don't want to stop my loading to mail something back to Lee for a fix.
Believe me, you will break decapping pins. Maybe not many, but one or two. You are creating significant force with that press, and if a pin hits something that won't move, it breaks.
All of the major die sets are compatable with all of the major presses. Shell holders aren't. Your shell holder will be specific to your press, and you will need one for each family of shells you use.
Choice of die manufacturer is personal, and largely dependent on the degree of precision you require, especilly in bullet seating. Competition loaders have one set of requirements, cast bullet loaders have another. Unless you are going to go specialized, it won't matter to you.
Welcome to the flock, and get that brass you've saved for years re-filled so you can shoot cheaper!
Wayne