Which would you recommend over the other?

Looking to replace just the rear sight on my 17 with either the Warren Tactical or Sevigny carry rear sight.  My 17 has factory night sights.  Will the replacement of just the rear match up OK?  Assuming it does, where can you buy just the rear.  Everyone I've found is a front/rear set.

Thanks

Warren Tactical on two of mine.  Reasons for me are, black rear, fast profile leads the eye to the front side, good side to side vison when moving from target to target.  The Warren shape is not an accident, Dave wanted a flat rear blade but Scott's rear sight is sloped and rounded and to not have any hard edges to slow the eye down.  The only hard edges the top of the front site.

You need to get the set, you will not be happy with the stock front and warren rear.

thanks