I forget who this is, but some forum member has bowls that they put opposite the food bowls because the bunnies like to poop while they're eating. Is it you Stan? Maybe it's SOOSKA or Naturestee? I forget who exactly.
I think suspending the bowl above the litterbox would be good, like one of those things you put on the tub when you're having a nice soak but want something to rest your book on, if you know what I'm talking about. The bowls that attach to the cage would be good too. To be honest, I just put the bowl with pellets down right in front of my bunnies' faces when it's pellet time in the morning, and for Muffin, that's usually right outside of the litterbox. She sits in there and reaches out over the edge to eat. I also use something called plastic canvas to keep poo and pee separate and keep feets out of the dirty litter.
My bf's bunnies, Frida and Benjamin, have a a giant litterbox/hay nest. They kept on taking the hay out of racks and making nests of it on the cage floor, and then peeing in them, so he took the top off one of those super pet cages and just fills it with wood stove pellets covered with plastic canvas, then a heavy layer of hay on top. The pellet bowl and veggie bowl and water bowl just go near the front edge of the box (they prefer to pee along the back more than the front). This helps too because they like to knock over the water bowl, no matter how heavy a crock we give them, so he can kind of submerge it in wood stove pellets that keep it upright and absorb any spillage. They don't ever pee in the food bowls, but sometimes a poo gets in there, I think mostly from being flung about as they jump.