This is very personal. Even if you measure bone width or have a length you like you might prefer a more or less rounded shape.
Right now my family has parents and 3 kids sharing same 9 bikes. Everyone likes WTB Pure models with mixed opinions on the Volt and Speed models. The firmer padding is better but I doubt I'll spend on titanium or composite rails again. Crashes and use have never broken a chrome-moly rail saddle the way fancy and cheapest ones have broken.
As for shops, I always support our paid up sponsor shops and they've always been great. You can call to know who has the most but I suggest visiting them.
You can measure to know what width might be best.
I believe we're all XC riders but one who's also on a race team. Dropper posts and good shorts or liners are part of the comfort equation too. For relief? It seems to me like getting out of the saddle and dropper posts are where much of that comes from. It also seems like modern bikes and setup make same saddles more comfy but that's personal too. The low, slack, wide bar and short chain stay and short stem bikes make same saddle better for me.
Same WTB saddle on my old school bike vs modern trail bikes is more comfy. Other will feel the opposite so have fun trying stuff! Go do demos. There's one today and more on the calendar.
