actually, yes. There are 2 that i know of that will keep up with 12 or so. The empire Reloader (not realoader , and the halo Backman. I used to have a backman, it worked fine for my slow spider i had, but it was inconsistent and i got a PMR =P.
as for the balls feeding 4 at a time, try checking your detents. If you take off the eye plates, there should be eyes and little rubber nubbins, those are your detents. if you take them out, make sure that they come to a point aren't too rounded, this will allow balls to be fed 2,3,or 4 at a time.
Yeah, i think thats it. I looked into it and mine are almost non existant, lol. So im going to buy some spring loaded detents, thats what ive been told is the best. Thanks.