First you have to decide which type of diet appeals to you as far as convenience, time commitment and cost and then Schrodinger will negotiate with you about whether or not he'll eat it.
Here's a few things to try if you don't want to go all raw:
add small amounts of the pate into the chunky he likes to see if you can at least get him eating more variety, perhaps he'll eventually eat 1/2 pate and 1/2 chunky or some version thereof;
stop the kibble or at least don't leave it available 24/7. Having food available 24/7 interferes with his ability to properly digest and feel hunger;
find other chunky brands to add to the chunky he likes -- it's kinda hard to find chunky stuff;
add some cooked or raw meat chunks to his food.
If you want to go all raw or part raw/part canned, start adding small bits of raw meat into his canned. Definitely stop the kibble. Read the info here
http://www.rawfedcats.org/nature.htm to ensure balance of meat/organs/bone which will become important if the majority of his diet changes to raw.
You can also try adding Feline's Pride or RadCat to his canned. It's mushy, not chunky, but it will get him used to the flavor of raw. Process is the same as adding meat chunks -- start with small amounts (1/4 to 1/2 tsp) and slowly increase the amount of raw and decrease the canned by the same amount. If he eats the mushy raw add in raw meat chunks and continue decreasing the canned to try to get him on 100% raw. Then you can start decreasing the ground raw and increasing the meat/organs/bones.
Or you can try whole prey either as the main diet or in addition to canned or meat/organs/bones.
I think it's important to always add a supplement to food as extra insurance that all nutrients are being supplied. I've tried a few and my guys like Mazuri the best.
I'd like to try some raw options for him, but I don't know where to start. Any advice is greatly appreciated by both of us!