Did you know you can play both?
1.e4 c5 2.Nf3 e6 3.d4 d5! And your have created a successful French-Sicilian hybrid, And with this move order, you have tricked white out of playing many of his popular/favorite lines in the French.
Sicilian or French
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Given your specifications, may I suggest the Caro-Kann.
The Sicilian is vast and full of tactics, wherever you turn. The French is less so, but plenty tactical at times. Plus you must enjoy French structures -- some do, some don't.
The Caro-Kann is absolutely sound and is largely oriented to positional play. Capbalanca, Botvinnik, and Kasparov all used the Caro-Kann as Black at times in their careers.
I play the French, it is awesome, however it can get tiresome, so i am learning the Scicilian,
LOL! Try not to get too tired trying to study all that Open Sicilian theory and don't forget all those annoying anti-Sicilians.