In the town my players are in has a blacksmith and a weapons and armorer shop that are conjoined. I want the weapons shop to have items like armor and swords and stuff and the blacksmith be where the can order custom items, such as pet armor. the store owners are brothers and the blacksmith provides the stuff for the shop. the problem is I can't think of a good race and personality's for the shopkeepers and I'm really stumped. and the next session is really soon ): 

I always think of blacksmiths as Dwarves. 
maybe the shopkeepers could be human or make up Half-Dwarves. They could be full brothers, while the full Dwarf could be their half brother or father. 

Just been mulling this over while cooking and thought, maybe a way of approaching this is through some questions...

• How cool do you want it to be? How often are your adventurers likely to return? Where is it? Who patronises them? (Shops there) 
• What are the economics of where they are? Are they a Lionshield Coster doing alright stuff for an alright price? Or something different? How much competition is there?
• What are the local races? Are they from here, or further away for some reason? Where do they get their stuff from?

I'm a fan of ripping stuff off... a few thoughts from the top of my head

• A master smith (Dwarf) with much reknown that can command high prices - turns out the real star is his female human apprentice (Think that was the Witcher?)
• An elven/half elven swordsmith - the best - but actively won't sell you stuff unless you earn his respect somehow (side quests - also Witcher I think)
• A Gnome Artificer - completely loopy. Prefers to deal with small folk. Hides jokes / tricks / features / effects in what they make
• Half Orc, highly intelligent, master crafter, well spoken. Will ask the party about their run ins with greenskins / goblinoids and either will/won't deal with them
• Lionshield Coster type - Run by recent human settlers, shunned by the locals (they probably look different / are from somewhere else) but are total honest brokers and could do with some business

Hope that's helpful as a starter?

Can't think of a good race, use a "bad one". 

Traditionally the ones people most likly to think smithing would be dwarves, gnomes, and humans.

Less likly Firbolgs, elves, lizardmen. 

Maybe cut strait to it, and have the adoptable goblin be one or both of the brothers. 

I already used a goblin for another shop keeper but I get the point

How about an elf? Plenty of elven master smiths in Tolkien’s works. A Drow or high elf might work. 

A Goliath with a connection to Fire Giants would work. 

A Fire or Earth Genasi?

Is there a particular cultural flair you want the weapons and equipment to have? I mean technically any race can be a blacksmith, if you want more delicate looking equipment with an artisanal flair you could always have elves, dwarves for more sturdy looking stuff, fire genasi twins is a fun option for a blacksmith due to the nature of heat and fire being a large factor in blacksmithing. But I think you might be overthinking it, if you are truly stumped you could always just make the blacksmith a human with a funny hat who is like the rain man of smithing while his brother is the face of the shop and sells the wares.

Quote from loltanner1 >>

I always think of blacksmiths as Dwarves. 

racist

An Ettin.

One head specializes in selling, the other specializes in crafting. 

I made a race - I forget their name, but they were essentially like driders, but gnomes, and entirely unlike driders. So gnome upper body, but with eight legs, and a disturbing tendency to lower themselves from the ceiling on silken strands. 

Neat, in shirt, vest and with a pocket watch and spectacles. Very very excellent tinkers. Of course, the one I actually used was a cartographer - but still.

Given that sibling Genasai don’t have to be of the same type make ona fire the other an air or water. Or make one sibling a Genasai and the other a tiefling as different parts of their heritage are exposed.

That is some pretty messed up heritage !

This is sort of unrelated but I have been playing around with quality systems. Something like a poor quality normal quality and  quality product. A low quality weapon will break on a nat 1 attack roll and after that becomes a -1 weapon (reparible with the otherwise useless whetstone). A normal quality blade is normal. A high quality weapon I have currently been giving one or more applicable weapon masteries (from the 2024 dnd) which has so far seemed appropriate. May or may not be helpful with these smiths.

When you're truly stumped, you can always just roll for it. There are tables for just about anything you can think to ask out there on the internet. Sometimes getting a weird result can make for a really interesting and memorable character.

A Harrgon with the personality of Bugs Bunny

Quote from SaintofM >>

A Harrgon with the personality of Bugs Bunny

 That demands payment in carrots - which are naturally hard to find because he is the only farmer. However he is willing to sell the carrots to the party for a "special price".