No doubt, welders gloves are the way to go.
I worked as a welder for a short stint and learned there is a difference between the cheap and expensive gloves; the more expensive gloves will insulate your fingers from the same heat for a few more seconds and won't dry out, shrink, get stiff, hard and brittle as quickly. But, for fireplace and wood stove work any welders gloves will be just fine and last at least the season with a little common-sense. A $10 - $20 pair can be had at just about any Hardware, Fleet, Farm Supply or Home Improvement retailer, also at most lumber yards and even Sears/Craftsman stores.
Something to think about...
Welders gloves are a compromise between finger dexterity and finger protection; different brands/models take this to different levels. It pays to check a couple places and try them on, test for finger movement and such. For wood stove work I like 'em softer and more flexible (a bit less insulation), with rough(er) type outer leather for handling wood, stove tools, controls, etc. Also, don't just buy the pair sitting on top of the pile, sort through them looking for the best leather... feel them for "thin" or overly stiff places in the leather... you get the idea. If you find some you really like, buy more than one pair... because sure as the wind blows they won't have that brand/model next time you need 'em.