It was Chris Latta as Cobra Commander, although he used an alias in the credits. Sgt. Slaughter voiced himself, of course. Not sure about Lady Jaye.
Overall, in my opinion, the DIC series was vastly inferior to the Marvel/Sunbow series. The background music was repetitive and uninspired to the point of being massively annoying, the storylines were clearly written for an even younger audience than the original cartoon, and even the animation itself looked -- for lack of a better term -- flatter than the Marvel/Sunbow series.
There was little in the way of character development. The Cobras, even Destro, generally acted like idiots. Even some of the Joes seemed to have their IQ's lowered somewhat.
Some episodes I sincerely could do without ever seeing again -- "Kindergarten Commandos" -- the episode where Hawk is replaced by an android... that starts making jokes -- the episode where Grid-Iron challenges a Range-Viper to a Joe vs. Cobra football game -- the episode where Ozone gets turned into a giant bug... etc., etc...
There were a FEW high points. I rather liked "Chunnel", which featured Cobra trying to conquer England and successfully kidnapping the Queen. Ironically, this episode first aired the day after a friend of mine from England arrived for a visit. He liked the episode, but pointed out a few inaccuracies

. Nevertheless, the episode did feature Big Ben and Big Bear, so it was hard to dislike it too much.
And there was the two-parter where the G.I.Joe Team and Cobra teamed up -- if reluctantly -- to take on the HeadMan and his HeadHunters. For a DIC two-parter, I thought they played this very well and appropriately kept the comedy to a relative minimum. It was a serious topic, obviously.
I will, however, maintain that the funniest line in all of the DIC production was during "Operation Dragonfire", when Gnawgahyde was cutting loose with the weaponry on board a Conquest, and remarked, "I haven't had this much fun since I mowed me lawn with a flamethrower!"
On the whole, though, the DIC material just doesn't hold up as well as the Marvel/Sunbow by any means. I think the best thing that can be said about it is that it gave some animated time to some later-year characters that probably wouldn't've gotten much media time at all otherwise.