It is to be expected that his morning BG is higher than you would like. After all, the corn syrup and dry food is in his system.
As you are in Canada - it is possible to use lantus, levimer or even prozinc. What I suggest is that you talk with your vet about changing to one of these insulins and if the vet is unwilling, then you need to shop around for another vet who will work with you.
I also suggest you go to the forums on here for each of these insulins, so that you can learn more about them and how they work. It will help you when you talk to the vet, to tell the vet which one you want.
FWIW - lantus and levimer are very similar insulins - in that they are both human insulins, many people follow the tight regulation protocols and you use U-100 insulin syringes - (get ones with 1/2 unit markings).
prozinc - is made for the animals, you can still follow a tight regulation, but it is a little more forgiving and allows a bit more leeway in dosage. You typically use U-40 insulin syringes - however because they don't have 1/2 unit markings and if you end of microdosing you need that - you need to get the U-100 syringes AND convert the dose according to the chart:
http://gorbzilla.com/conversion_calculator.htm
It's easy to do and will come in very handy.
All three insulins, are longer insulins than caninsulin, meaning they should last up to 12 hours unlike caninsulin. No matter what insulin you get, follow the mantra - start low and go slow - meaning start at a low dose 1 unit or less and when adjusting dose, do it in 1/4, or 1/2 unit increments - that's the go slow part.
And diet is a key factor as well. we recommend wet/canned food diets that are under 10 carbs - see Binky's chart for details. And this is good to feed all your cats with.
Hope this helps.