I don't really see the need for this considering that most people group up and despite being a low-magic setting, there are casters everywhere to buff you (and failing that, there's probably someone with UMD and scrolls). However, if you had to add some in, I'd say you'd be better off adding a 1 use/day spell like Bull's or Cat's at lvl 3. Under the current system (if I'm not mistaken) it would give you the ability to gain a 3-minute boost to those stats every two hours or so, which is more than reasonable. But even then, is it really necessary to have this stuff? I don't think so, personally. Granted, being encumbered can be a pain sometimes but again, that's what grouping up is for.