Not sure about your exact scenario, but aren't the Experts' sights lower than the Tactical because of the milled slide? Not sure how much, but it wouldn't surprise me if the height over bore is any taller than the standard USP.
So you should just be figuring for a Jet Funneled USP (might make it easier to find someone who can help that way)
So you should just be figuring for a Jet Funneled USP (might make it easier to find someone who can help that way)