It is difficult to find one single setup, especially for spinning, to target all five Pacific salmon species. Surely you can get a heavier setup for chinook salmon, but it wouldn't be as enjoyable when fishing for smaller species such as coho and pink salmon. The Stradic 2500 is an excellent reel. I bought one in 2001 and it still runs smoothly when being used. That reel size is perfect for pink salmon, adequate enough for coho salmon, but for chum and chinook salmon it is a bit undergunned. For chinook and chum salmon, my preference is a baitcasting setup.
Back to the rod option for the Stradic 2500. I would go for one that is around 8' to 9' long. If you intend to use it for casting and retrieving lures, then you definitely don't want to get one longer than that. A longer, heavier rod would tire you out when you repeat the casting and retrieving motion during your trip. Find a rod that is rated 6 - 10lb test. 8 - 12lb test is fine as well, but that's slightly overboard for pink salmon. I have spinning rods in both specs. The 6 - 10lb test is always used for pink salmon (sometimes I use a 2 - 6lb test, or 4 - 10lb test).
I recently got a Shimano Clarus CSS90ML2B, rated 6 to 10lb test, 9' long. It has been sitting on the shelf and I am dying to use it, hopefully for pink salmon later on this year or coho salmon on the beach. Last fall I was using a Shimano Clarus CSS86M2B, rated 8 to 12lb test, 8'6" long. It was fantastic for coho salmon, even caught a few chum salmon on it. I find it a bit heavy to cast my usual light spoons, but was still able to achieve the distance I wanted.