Sev,
We can debate food choices until we are all blue in the face, everyone has their personal preferences, and what their own personal budgets and their cat's particular likes and dislikes. So it really comes down to finding something that A) Your cat will eat, B) That fits into you budget and C) that is under 10% calories from Carbs for your diabetic.
But there is WAY more to dancing with a sugarcat than just diet.
You have already been started on a good insulin and at a good starting dose.
The third key to this whole process is test blood sugar levels at home to know if Kitty is receiving enough or not enough insulin. This is purely my own point of view but I would stop over analyizing your cat's menu and pick something he likes, that is under 10% carbs, and fits within your budget to feed both cats. And start considering getting a meter and start testing him at home so you can start heading him in the right direction towards hopefully remission. Especially while you are doing a diet change and eliminating the dry out of his diet and finding that perfect food. Since food can and does have a major role in the way their bodies respond to insulin therapy I would want to be watching for trends in his readings as well as collecting data on how he is responding. It is also the single best way of making sure he is safe while on insulin. I would also want to be testing his urine for ketones, as these can lead to a potential fatal condition known as DKA.
If you are hoping for remission in Kitty then you need to have all three elements in place, diet, insulin and home testing. Also we can't help guide you on adjusting and tweaking Kitty's numbers to give him the best possible shot at remission until you start gathering data on his blood sugar reading to share with us. I know first hand since I adopted both of my sugarcats as diabetics that had I know been testing at home I could have very well seriously injured or even killed my Maxwell, because he so quickly went off insulin and we had no history together for me to be able to pick up the subtle personality changes that would have told me hypo was coming on. The same can be said for my Musette, I have on a couple of ocassion only been able to intervene it was could have become a serious hypo situation because I was monitoring her at home, because a couple of times she has taken a seriously low dip into the low 40s and even 30s with no outward signs of hypo.
Diet can always be tweaked as you go along, because every cat is different, what may work for one will not always work for another. I have a very delicate balancing act that I play here with feeding 13 cats, which include one diabetic in remission, one currently insulin dependent diabetic, one non-diabetic that is highly sensitive to anything with grains, 2 that are allergic to chicken, 1 allergic to eggs, and yet another one that is allergic to beef. Even among my two diabetic, one can easily eat things as high as 7-9% carbs and not spike in BGs, while the other one if she gets over 6% carbs will dramatically rise in readings. I am also feeding cats ranging in age from 18 months to 15 years old. I'm also a full time college student, wife, mother and grandmother, and thus we are working on my husband's single income at present so for us it came down to what they would eat that was within our budget that would work for all the various health concerns.
As far as quality of ingredients since many of my cats are former ferals and ex-barn cats...I'm pretty sure they never asked the mouse or sparrow they had in the wild to produce a USDA certification before comsuming it for dinner, and they certainly didn't mind eating said mouse or sparrow's "by products" in fact I have seen them on several ocassions leave nothing but the tail behind when having a rodent appetizer.

At least for myself, I try to remember that these are cats, and in being so the only real difference between them and their distant cousins the lion and tiger is size. They are still very much one of the ultimate predators and obligated carnivors as well as skilled hunters and killers. Humans are about the only mammal on the planet that worries about the makeup of their diet, we as humans tend to over think everything.
Mel, Maxwell, Musette & The Fur Gang