i'd shoot down the base, then get some sg150 to shoot the flake w/ and then shoot 3-4 wet coats of clear. after that's cured, i'd sand it flat w/ some 600 grit (watch your edges, don't sand through) and then after it's (the clearcoat's) flat, i'd shoot another 2-3 coats of clear and sand and buff
shooting flake-
remember that the flake falls, so if you're trying to shoot it underneith something, you won't have much success. after my basecoat is dry, i'll usually start w/ the bottom of the tank and put it on a towel upside down and shoot it till i'm happy then let it dry and put it on my stand and blend the flake in w/ that. i'm talking about huge flake, not flake that you can get in a basecoat of silver or something like that.
good luck and do a test pannel if you're unsure of things. hands on is the best way to learn.