Ok bro, not being an ass but let me point out some facts that are most probably not true.
I seriously doubt You 5% BF at least not all year round and it would be unhealthy if you was.
Theres no way in the world 145lbs is anywhere near your natural potential (not even with the worse genetics in the world) all that fast metabolism cant put on weight is bullshit, it doesnt work that way.
Gear is not gonna do anything if you cant get past 145lbs naturally
Now then, I understand that you think your eating all day, this is probably not true, I will post you up what i eat in a day and you can see what eating all day really is

.
Unfortunately, if you want some gains, the Abs are probably gonna get a little invisable anyway, you cant have it both ways (well you can but its complicated)
Can you please post up your diet in the nutrition section and we can probably help you out a bit more before you consider jumping on the gear.
Lizard gave some good advice there.