"Next week I will be camping in Rocky Neck State Park in CT which has a nice beach, saltmarshes and a river flowing into the LIS. Seems like I would be able to fish all of them but need to pick up some gear for saltwater."
That is very hard to figure. you're not going to want a 10-11 footer for the marsh, nor a 8 footer for the beach.
I think I'd recommend a 9 ft, with a better quality braid friendly reel.
Perhaps something along the lines of a Tica 2-4 (3 1/2 oz would be the sweet spot) and perhaps a Penn Sargus reel. All toll, that would set you back around $200 and include some decent 20# braid, spool of 40-50# leader material, quality swivels, and a few pkg. of good hooks you can snell to the leader yourself. Maybe a few fish finders too if inclined. (all for about $200)
Here's my reasoning as to why;
BEACH - Plenty of muscle to work a kastmaster hopkins in 2-3 oz, sling smaller (12-14" eels w/o weight, sinker and clam, sinker and worm, plugs in the 2-4 oz range. You'll be spending most of the fish time in the wash out to the back of moderate waves. I feel that's where you'll find most of the fish in the early evening until sunrise. (you'll probably not be able to fish the beach in the daytime)
RIVER - could use the same stuff as above, and maybe a drifting head, or eggs with teasers, and combinations of most. Should be a very good choice for that (IMO)
MARSH - these are usually smaller schoolies, a 1- 1 1/2oz. surface popper and droppers (redfins etc.) are killer here at times. May also like to try floating a worm or clam on a egg or dobber in here. Something I like is a blacked out 1 oz. kastmaster (hookless) tied in as a casting weight and followed by some flatwing / shrimp flies etc.
I feel this would be a good general purpose rig, really a nice jetty stick too.
Later on if you decide you'd like to specialize in one particular area,, I doubt this would sit collecting dust when just scouting about.
Good luck & enjoy.
I look forward to a full report on how many fish you caught to the point of your arms felt like they were falling off.
By the way, when I am just out playing around it's ussually with a 8 1/2 ft conventional or a 9 ft. spinner. Handy, easy, and a lot less trouble to carry than a 10-11 ft. surf rig.
However, in the fall migration it comes along but rarely gets wet. That's a different ballgame.