You may find that other folks make their own semi trigger and sear combos, but I'm here to tell you that Tomt / KMP are TOP NOTCH! They SET the standard that all these other people WISH they could attain!
Now the UP side to buying one of those "other" company parts... You'll get your lesson in customer service and maintenance on your weapon with them!
Get a KMP setup! If it breaks, Tom will likely send you a replacement before yours is still in the mail back to him! Never mind that they RARELY break, unlike others that are made of lesser materials and/or workmanship!