disk brake kit

Ralleys fit just fine its getting ralleys

Sure, but now you're buying rims.

And if you're going to buy a front disk conversion kit AND rims, then, you're not all the far away from a full BBP conversion. It's one thing to stay SBP if you don't have to buy wheels, but, if you have to buy new wheels you might as well go BBP. More wheel choices, no worries about finding a set of rotors later if you need them, no worries about whether or not they'll be making the SBP rear drum stuff when you need it, etc.