to get your bench up, i would work them out twice a week, like monday and thursday for example. monday, focus on strength - 4-6 reps and barbells, thursday do 8-12 reps which is more mass oriented with dumbells.
big arms require the following exercises
chin ups, shoulder width
cheating barbell curls
close grip bench
reverse grip tricep pushdowns
the rear tricep, which is activate by reverse grip pushdowns accounts for roughly 20% of your arm mass. if you haven't done them before its an easy way to add some size
also, let me add here, that tren is great for a recomp, just like havoc/epi and h-drol. if you cut your body fat down some, you would have a higher testosterone release, as well as higher growth hormone release. google search "growth hormone and belly fat" or "testosterone and belly fat" for more information. once you cut down to 9% body fat, you'll notice the difference.
i feel kind of silly offering advice to someone with bigger arms than me. hopefully the information helps.