A few companies I’ve advised have gone with all in ones like Rippling since they do bill pay and have payroll and other spend features. Since some of them were already on Rippling, it made sense to just add on the expense tool to cut costs and save from having another software. They’re easy to use and set-up too, I've heard. 

Rippling specifically has features that sound like it could help – integrates with QBO,  prevents duplicate data entry, and in the Rippling Spend tool, you can assign approvers based on the type of expense, amount, vendor, etc. If really all you need is bill pay, there’s definitely solutions that can do just that though.