Next to 50lb. braid, 65lb braid is probably one of the most useful sizes when it comes to fishing both fresh and salt. I have a Abu Garcia Record 60HC spooled with it. The entire 300yd spool fit on the reel. I use it for big salt and fresh water fish. Everything from land locked stripers and whisker-kitties (ie: big flathead, blue and channel cats) to salty species like bull reds, monster stripers (40"+), togs, sheepsheads and black drum.
I also have a Shimano Curado 200 DSV spooled with it and use it as my froggin and heavy jig setup. I can cast a Stanley Ribbit close to 40 yards with it, but I can also use it for fishing heavy jig-n-craws and nasty cover.
Find yourself a good used Citica or Curado (silver ones) and pair it up with a good 6'6" - 7'6" MH/XF rod and don't look back.
As far as reel type, in order to use 65lb braid on a spinning reel effectively, you are most likely looking at either a surf casting rig or heavy boat rig with a 5000 series reel or higher. Most folks in the Chesapeake Bay that fish out of a boat use a Shimano Saros, Stellas and Baitrunners or Daiwa Saltigas in the 8000 class for line that heavy.
In a kayak, I have the luxury of allowing the kayak to act as a form of drag, so I don't need as large of a reel or line for that matter when it comes to spinning gear. The largest series spinning reel I own is a Stradic FJ3000 spooled with 30lb. PP and I use it for reds, speckled trout, striper, bass, etc.....
For everyday fishing, 30lb PP is the most you need. If the cover is not too thick or gnarly, then you can actually get away with 20lb, even for froggin.