For concealed carry, I wouldn't add one to a Gen 5. They get rather wide due to the way they are designed to fit over the flared magwell. If you do want to get one anyway, I second the SLR or ZEV. I have not yet used the SLR, but seeing photos of it compared to the ZEV (that I have used), it is a little sleeker.
The Dawson magwell is going to be too large for concealment (for most people).
And since it was previously mentioned. Once you add a magwell, you are pretty much dedicated to using magazine extensions. Stripping out factory magazines is extremely difficult with any larger magwell.