they are both k type thermocouples which will cover the roasting temperature range just fine. thermocouples are made by using two dissimilar metals which create the thermoelectric effect that can be used to measure temperature. So the composition is the same.
All thermocouples are going to vary from unit to unit ever to slightly so it is best to calibrate them before hand. The best calibrator is water! ice in a funnel that is melting will have water that is precisely 0 deg C! similarly water that is on boiling will be at 100 deg C. Assuming close to sea level :)
Either part will be fine, get the cheapest one! just make sure the cable is long enough for your needs. You mentioned you already have a adapter for your DMM so you wil be fine to order them with regular thermocouple connectors.
Symbols: = New Posts since your last visit = No New Posts since last visit = Newest post
Forum Rules: No profanity, illegal acts or personal attacks will be tolerated in these discussion boards. No commercial posting of any nature will be tolerated; only private sales by private individuals, in the "Buy and Sell" forum. No SEO style postings will be tolerated. SEO related posts will result in immediate ban from CoffeeGeek. No cross posting allowed - do not post your topic to more than one forum, nor repost a topic to the same forum. Who Can Read The Forum? Anyone can read posts in these discussion boards. Who Can Post New Topics? Any registered CoffeeGeek member can post new topics. Who Can Post Replies? Any registered CoffeeGeek member can post replies. Can Photos be posted? Anyone can post photos in their new topics or replies. Who can change or delete posts? Any CoffeeGeek member can edit their own posts. Only moderators can delete posts. Probationary Period: If you are a new signup for CoffeeGeek, you cannot promote, endorse, criticise or otherwise post an unsolicited endorsement for any company, product or service in your first five postings.