I helped a friend set up his new Hornady LnL and I was quite pleased with how well it worked. I have the RCBS set up and I like it, I don't think you would go wrong with either one.
As far as powder goes, I have had really good luck with 4064 and Varget both with 165 grain bullets. Varget, 4895, and one of the Reloader powders seem to be the most popular choices. The sierra match king seems to be a very popular bullet as well.
No matter which set you get, get the others book as well. I would also recommend getting the complete hand loading book for the 308 ( I think that is what it is called, its about $9.00) It lists loads from powder, bullet, and mold makers, so you get a lot of good info for fairly cheap. it will list powder and bullet combos that Hornady and Speer do not list in their manuals. For example my Honrnady book does not list 4064 with the 165 grain bullets, but this little manual does.
Personally I have found that I really like the Hornady dies better than the RCBS dies, but I would like to try the X-Die from RCBS. It is supposed to limit the amount that a piece of brass grows. I am not unhappy with my RCBS, I just like the Hornady ones better.
One other thing I just thought of is that having the LnL feature while using a single stage press is a big bonus. While it is not a huge thing to have to unscrew a die, it is much nicer to only have to twist it to unlock it. But you pay for that as well since to really take advantage of the feature it would be best to get a set of bushings for each die set. My friend just has a set for the dies that he uses the most, and then swaps them out when he needs to use another set.
Either way I think you will like either press set up.
