Might be difficult to achieve, but I recommend you find somewhere with all three wedges in stock to check in person? - When I bought my 900 Forged set I loved the nice compact head of the PW & bought a GW to match without seeing it - When it arrived it was not just a GW version of the PW, but had a much larger head, which I didn't like - After chatting with my club Pro, he suggested the T7 50* was a much better GW for my set (which was the case) - So moving on to the 919 Forged, perhaps the GW is similar to the PW, but it might not be & the S18 might be a better fit?
The S18 is a specialty wedge, meaning it doesn't belong to a single set, it's more like you have every loft available, go for a fitting, find out your yardage gapping and go for the loft that fits that gap. It's the Silouette Shape wedge, arguably a bit more "MP" orientated as the other two.
The 919 Forged Wedge should give you similair looks and feels to your 919F Iron Set, the gapping should be constant, as I am sure they have robot tested the lofts to give you good gappings and it is forged.
The JPX Wedge arguably sits more in line with the 919 HM Range, isn't forged but cast, but might also be an alternative, depending on what you are looking for. Looks and feel should in term be different from your iron set, but it may be what you are after. I would recommend you go and hit all 3, or at least look at all 3, and go with the one that makes you want to hit it the most.
The reason they are at different price points are probably as follows:-
1.JPX919F- Wedge is classed as part of the JPX919F set and will be priced as an individual iron from that set.
2. S18 Wedge is a forged option with a small amount of Boron and will be priced as an individual forged wedge.
3.JPX919HM. Was designed as a general purpose wedge that can be blended with the 919F's and is made from X30 steel and not forged.