You can put a peep on either rifle.
You could always scope a 336 easily, and on the newer 94's, you can scope them easily, too.
The Marlin is a bit heavier, and has a pistol grip. The 94 is a bit lighter, has a slightly slimmer receiver, and in most models has a straight grip.
Flip a coin
Or, better yet, handle both and buy the one that feels best. There's no wrong choice here.