Your best bet is to wait until Apple's Volume Purchase Program is available worldwide, which will no doubt happen fairly quickly. I'm in australia and can't wait for it myself.
Until then, there is no good way to do what you're looking for except for the employees to purchase the software and be reimbursed by their boss. Since most apps are only worth a few bucks, and almost never over $50 or so, that's not such a big ask — compared to the tens of thousands per year already being paid to each employee. You could also take advantage of the gift voucher feature, to provide employees with the funds prior to them purchasing the app.
Having a personal Apple ID in addition to one that the business controls is not a good solution. My phone is registered with three different Apple ID's and it's not for the feint of heart, you can do it but it's a hassle. And there's not going to be any way to transfer those licenses over to the VPP system once it's available.