A vented loop should solve the problem
Depending upon how far above the toilet, a vented loop that's at least 8-12" above the inlet port on the unit should allow you to put it there. You'd need a vented loop there anyway, to prevent runback into the toilet while heeled...unless you want to put the treatment unit above the whole toilet, just put it a few inches higher.However, I strongly recommend that you talk with Vic Willman at Raritan (800-352-5630 x 6) about any deviation from the instruction manual and all other installation issues.