There are many outfits to buy from. I like "West Coast", they have a big variety. Shipping is significant, so you probably want to buy 3 or 4 soaps when you order, and those will probably last you a couple of years.
I have bought a lot of soap made by Stirling. The lather is good, and they give you 5.8 ounces of soap (most people give you 4.0 ounces), but they are often too aggressive with their scents and use of menthol. This of course is a matter of taste, but I enjoy a bit of balance in these things.
Ogallala bay rum is a wonderful soap. Good lather and smells wonderful.
Ghost Town Barber by chiseled face is a fantastic soap.
Ozark Mountain by Stirling, is great and my favorite of their soaps I have tried.
Be aware that there are two dimensions to shave soap. One is the base, which produces the lather. The other is the scent. A great soap gets both right.
When I use up my current supply (which will take years), I'll try others on the Sharpologist list.
Logbook Barrbarr (traditional barber shop) Lonestar
Spartacus Vanilla Vendetta Kaizen Woods and Spices Barbiere Classico (traditional barber shop)You can order direct from them! Their website checkout wants $4.99 shipping charges. The price for Spartacus is $19 on their website. Shipping jumps up to $7.64 when I add a second soap. The price on Amazon is the same, with $4.99 (West Coast Shaving) shipping.
I was delighted to order direct from their website. Shipping was only $4 for the two soaps! (The soaps are 4 ounces and $22 and $23 respectively). Sent to me via USPS.
Amazon would have sold me Tirsmegistus, but for $27 and adding $5 shipping, so I am saving $8 by buying direct! (Actually, it is West Coast Shaving offering products on Amazon). Declaration Grooming is in Ferndale, Michigan.
I get tempted to try some of the offerings from Phoenix Artisan Accoutrements. They are in Arizona and well regarded. Their website is a tangled mess, and for whatever reason, when I look at their stuff (or manage to) I decide to go elsewhere.
Tom's Shaving Info / tom@mmto.org