My preference is for PW   50 54 58 .  In the Northwest  U.S.,  when the weather is good I switch to a sm5  58 8  M wedge but with wet , windy or colder weather  I use the sm5 58 11 F wedge.  I found if you open up your 54 a little bit it plays like the 56 and more flexible for longer bunker shots. The 58 is a terrific wedge just play with the bounce. I have a bit steeper swing and am fairly tall so the F wedge works best for my swing. I would definitely ask a golf instructor look at your swing and suggest which bounce works. Weather can play havoc on wedge selection in the wind as we know too .  

I use to carry a 50 / 56 / 60.  Then I decided I didn't use the 50 enough so I pulled it and went to a 54 / 60 and added another hybrid.  Of late I've pulled the hybrid and went to a 54 / 60 / 64 and the 64 has made more difference than any other wedge.  I took a tour model 60 degree and ground off the bounce (for the most part) so the leading edge sits on the ground.  It's allowed me to get up and down when I miss short side so many times it's not funny.  Especially for the guys that have to pay to see it!  You can't be afraid to take a big swing from a short distance and you must stay relaxed, big swing and stay relaxed. 

The other place it helped me is in our bunkers.  We have hard bunkers, very little sand (cheap owner won't give the greens keeper any $$$, and it's a private club no less!) and it's the only way to have any control out of most of our bunkers.

Bill B I have several wedges 49,50,52,56,60. We have been getting a lot of rain in Fl. and I tend to change wedges with the weather 60 in traps when the sand is compacted 56 out of the heavy rough 52 out of the frog hair. But I find it is best for me to adjust according to weather conditions.

If you like the the 50, 54, 58 set up but miss the 56 have you considered going 50, 56, 62?

I have traditionally played PW (47), 54* and 58*. I don't believe I need any more than those lofts and certainly don't feel I'm missing a gap wedge. I can flop the 54* and 58* as well as let them run a bit. Full swings give me about 125-130 (PW), 100 (54*) and 85 (58*). Dialing down can put me just about anywhere I need to go. I had used a 54* Zing 2 W that I loved for its versatility and picked up a used Vokey SM4 oil can 54* to complement the 58 (raw SM5 milled)*. My sand play was marginally better with the Zing, probably due to the thin sole that almost disappeared when opened up, but I'm still satisfied with the Vokey. I walk and carry, so adding more clubs (I usually carry 12 or 13) doesn't appeal to me, or does it appear (to me) I need any more than I have. I have never wished that I had a different lofted wedge with me. However, I am thinking about having the 54* bent to a 52* or 53* (yes, I can tell the difference of one degree - just had my lies checked because they felt wrong and they were one degree off).  

I use vokey sm5 48,52,56 and 60

47 Ap2  54 sm5 m grind bent to 52 g 58

sm5

I use the SM5 56 degree with S-grind. I can use it with green side chipping and in bunkers. A very versatile wedge, also can be used for flop shots as well. 

I'm currently bagging - 50*, 54*, 58* bent 2* flat.  I have in the past moved my 54* to 55* to achieve my desired flight and gap.  I agree the 58* off tight lies can be problematic. Wish I could get the whole assortment and choose based on the course and conditions. 

I have a 46* Vokey pw so naturally for the best gapping i find 50, 54, 58 offers me the most versatility. i hit both 58 and 54 out of the bunkers. gaps are good, about 10 metres apart from 125 metres and down.

Go with your first choice.  I got fit by Titleist touring guys and need 3 wedges instead of the 54 and 60 I was carrying.  I ditched the 60 which was too much as I am not a wedge magician doing flops everywhere.