Wiking,
I believe that you need a sight .100" shorter than the one you have, or .330". Your idea of getting a .330" and a .380" is a good one. The standard ramp sight is available from FA in those heights. You should be able to return the .430" they furnished you, for credit but the cost of return from the RSA may be a hindrance. A brass/gold bead front sight will work with either the "V" Express sight or the square notch rear. Although the use of the square notch is a bit unconventional, it works fine. The same is true of the fiber optic sights, however, they are of a smaller diameter than the brass/gold beads, and personally, I'm not a fan of them. Your opinion may be different. All of these are available in the same heights from FA, including .330", .380", .430" etc.
The notched severely undercut patridge front sight mentioned above by another poster was intended for use with a hood, and a silhouette rear sight (the notch held the hood on). It is no longer offered by FA, and was replaced by an adjustable post which would not be suitable to your application. The undercut was also so severe that it tore up holsters when used without the hood (and the hood wouldn't work in a conventional holster).
With your short barrel, a standard FA ramp of .330 or .380" may provide you with exactly what you want. To my knowledge there is only one undercut patridge available, and its undercut is not as severe as the old notched FA blade. Thus, it is more suitable for use with holsters, yet gives a blacker sight picture than a ramp.. I'll send you a PM on it tomorrow when I'm able.