no I'm not saying he is better. I believe he is better (kirin aside)Itachi hasn't shown any ninjutsu that puts him above Sasuke in that category so I really don't see how you can say he's above him in it. Sasuke has fire style jutsu, chidori and it's variations and kirin. Itachi has fire style jutsu and a single water style jutsu.
As for weapons Sasuke was matching Itachi blow for blow when they fought albeit Itachi was half blind they still matched each other. Sasuke also has his sword and is very skilled with it so more or less I give the advantage to Sasuke or equal at least.
we haven't seen much but I don't think he's beneath sasuke in katon. and do you actually believe that he has only one suiton technique? that technique was prasied by kakashi (who uses suiton the most in his battles). I think he also has some badass suiton, katon techniques we never had the oppurtunity to see from him.
aside from kirin they are either equals or itachi is better (as I believe) but kirin is the breaking point, unless itachi has something like that sasuke has the edge