thats the problem...if youre in America, i dont think too many people have enough control to spar with elbows (without headgear or pads).
why not use a full face like this? you probably wouldnt need to deal with elbow pads at all, though you could for the extra bit of safety...the only risk you run is catching an elbow to the jaw somehow and even that would be unlikely (even with uppercut elbows).
sure, its bulky but elbows are dangerous and can injure much easier than punches. probably easier to injure in comparison to sparring bareknuckled...most people have better control with their hands than elbows, id assume.