^^^ Yep, buy it. Or, send your carrier out to get ramped. There's a couple places that do this service. It's better for it over the long run to run a ramped carrier. Easier on hammer pins. Run KNS Anti-rotation pins, too, for the support to the hammer pin.
Also, how do your magazines hold in the lower? Standard AR mag catch? If so, consider buying some surplus UZI mags and modifying them - I've posted the template somewhere on this board. I have 10 of them, marked them, cut them up, and they run great.
Ramped carrier pics below.