Incinerators on terminators don't float my boat - the psycannon has range, can pop tanks & with 4 shots, the incinerators only real benefit seems to be removing cover saves, but given you'll get more shots with the psycannon, I'd go for it everytime.
In terms of swords/ halberds if you want to mix I'd go for:
Justicar
MC halberd
GKT halberd
GKT sword
GKT hammer
GKT sword & psycannon
5 sets for wound allocation. Some will say that giving the justicar a
MC hammer is the way to go, but given perils, it may be savvy not to kill your only dreadnaught killer with an unlucky dice roll...
EDIT:
If you're doing 10 terminators as 1 squad, the other 5 I'd do as:
GKT halberd
GKT x 2 sword
GKT hammer
GKT sword & psycannon