I think a feat is bad because you are making them 'pay' for something is usually 'free'. Most martial classes get magical items naturally by adventuring. You could just add it to Savage Warrior something like "Starting at level X, your unarmed attacks and attacks made with improvised weapons count as magical bla bla" which is how monks do it I think.
EDIT: I do like the gloves tho cause he could eventually upgrade it to +3 since, unlike monks, his damage dice doesn't increase naturally.