Hi,
I haven't used a Viper, so I can't comment directly, but I do have the Sniper 3 pce, 10' 6", surf rod and can comment on the build etc. The Nitro blanks are excellent and the build is very nice. The action is "as described" in the Nitro Innovator literature. I was very pleasantly surprised at how lightweight they are, while still retaining good strength. I matched my Sniper to a 3000 series Daiwa Luvias reel and it balances perfectly. I suspect that a 4000 reel may be a little on the large side for both of the rods you are looking at, whereas the 2500 reel would possibly work well on both rods.
Good luck with your research. I believe that you won't go wrong with Nitro rods. If in doubt, another brand to consider might be Samurai. I have three of their rods and, frankly, they are nothing short of sensational. Some of their models are a little bit over your stated price range (RRP) but with a bit of bargaining (haggling) you should be able to get close to what you have in the budget.
Cheers