Nothing wrong with that.
Ortliebs are the business and there's nothing wrong with stating that you don't need the super-high-end solution.
One note: the heel-strike issue is due to the chainstays not being long enough. I assume this isn't a commuter-spec or trekking-spec bike. You could look at a TUBUS Cargo rack which is designed to move the panniers rearward for bikes that weren't designed with commuting in mind.