οἳ ὧν μὲν σὺ δίδως χρημάτων οὐδὲ μικρὸν τούτων ἕνεκά means
οἲ ὢν χρημάτων ἕνεκα ἂ δίδως… or τῶν χρημάτων ἕνεκα ἂ δίδως.. it may also be Gen part.
Your second version is close. The relative pronoun (ὧν) is attracted to the case of its antecedent (τούτων) and χρήματων is incorporated from the matrix clause into the relative clause. Without attraction and without incorporation it would be ἂ δίδως τούτων ἕνεκα τῶν χρημάτων. Attraction and incorporation mark the relative clause as restrictive.