Both suggestions you've gotten so far as good suggestions. I lean slightly towards Shoney's suggestion, but I would use an RCBS Lockout die because if you get an over/under powder charge, it locks up the press and gets your attention. The Hornady die relies on you paying attention and visually catching the problem. Since attention spans are easily distracted, the RCBS Lockout is a bit better solution for powder charge safety.
That said, it's awful hard to get an over charge on a automatic advance progressive. But an undercharge, just as dangerous, is always a possibility if you run out of powder and don't realize it.
BTW, I'd hang onto that old three hole turret. You may find it comes in handy for inexpensive caliber changes on milsurp and other low volume cartridges you may decide to reload where you don't want to spend a lot of money to get reloading. Hard to beat the price of a die set and a single turret.
Regards,
Dave