300 deca x 10 weeks PLUS test 450 mg x 12 weeks
OR
600 test x 15 weeks.
I'd say a person would get more out of the deca/test combo. Sure, more test is great, but people stack things for a reason. The synergy effect of serious AAS makes a difference. And if your stuff is legit human grade as you say it is, it will probably be a good cycle.
That said, like Tbombz brought up, I wouldn't necessarily run that cycle for 12wks...16-20wks would be more like it. However you do it, if it were my cycle, I'd stop the deca 4wks before I stopped the test...it will make your PCT and transition into natural training much, much easier and smoother.
So your philosophy is go on for an extended period of time and not worry that when you come off you'll spend countless months in a low testosterone state suffering through depression, lack of energy and no libido plus accelerated aging from low hormone levels? Or you probably believe one should never come off and to hell with bad cholesterol, chronically elevated liver values, etc. I wonder one day if you'll still think this was all worth it just so you could look in a mirror and feel "big".
I've said for a long time that the way most people cycle is not the best way to get things done. Time on = Time off is the safest approach, and there is nothing wrong with doing it that way, but it is not the most efficient way to use your AAS.
As for depression, lack of energy, and no libido, the reason you see this in so many guys is because of the way they come off. So many of them will come off a cycle, stopping everything at once, I've said for a long time you're always better off ending a cycle on just test and dropping it down the last few wks....but beyond that, the PCT plans of many just plain suck. 3-4 wks of nolva, starting at 40mg/ed and ending on 20mg/ed, sure that PCT plan works fine after some cycles, it's probably the most common PCT on the planet, but for long serious cycles, it's probably the worst thing you can do...you might as well not run a PCT. A good PCT after a strong cycle should always be in the 6wk range, it should always include HCG at the begining even if some HCG was used while on cycle...it should consist of clomid for a first choice, if the person can't handle clomid it should consist of nolva at a higher dose for a longer period rather then the fast taper down many do.
Your comment on bad cholesterol, chronically elevated liver values, etc. First off, it's more common for guys to have problems with a lower good cholesterol when on AAS, but as with most things, with a sound diet this can easily be avoided. Liver values, you're right, they will be elevated, there is no denying that, but to the extent you take it is up to you...no one is forcing orals down your throat. Even if you are taking orals, if you do so in a reasonable way, cycle on and off your orals you will be fine. Oral AAS still won't raise your liver values as much as taking Tylenol daily will...plus, the liver is one of the only organs in the body that can completely rejuvenate itself if given the chance...this does mean you have to come off all orals to rejuvenate.