If you need more support, go with the regular footbed and do yourself a favor and get yourself properly fitted at a store that sells lots of Birkenstocks, preferably a Birkenstock store that also does repairs.  A Birkenstock "narrow" may fit many women's feet that are considered normal by any other shoe maker.  A "B" width is generally considered normal for women.  A B width is way too narrow for my feet.

 This particular pair was a bit more snug than another pair of Birkenstock "regular" (wide) 37 soft footbeds that I own, but that may just be the difference between a wool and suede pair?  My feet have been measured recently at a 7 1/2 women's D width, but in my 20's they were measured at a 6 1/2 women's EE, and E width.  I wore 38 regulars for years because my feet spread and measured bigger and it recently caused all sorts of problems with my arch on the foot that is a tad smaller, my hips, knees and back.  I went back to a 37 regular, with the regular footbed and the problems stopped within days.  I like the soft footbed, but I cannot wear it all the time because I need more support.

I'm hoping that resoling this shoe will not be a problem, but I know that having the footbed liner replaced in a soft footbed is not done. Having them resoled is less than half the cost of a new pair, even with shipping costs/travel time.  For a woman with feet like mine, it's nice to be able to wear a decent, supportive shoe that is not horribly expensive. With "cork life" care and timely resoling, a leather pair of Birkenstocks will last for years, one pair of Nubuck Arizonas lasted for 13 years with heavy wear.