Hello there!
I think most pro fitness and figure competitors dont use steroids, as far as I've seen so far anyway. Perhaps a little more of them do in bodybuilding?
If you're having trouble putting on muscle, the issue is usually 80% diet.
Now before you do something as drastic as taking steroids, i think i tmight be best to have a look at your diet and perhaps work out more than 3 times a week? You seem to have similar measurements to me, you might find you put on more muscle when you're at a higher fat percentage?
There are so many other things for you to try first, and I think if you take steroids when you're only working out 3 times a week, a lot of it will come on as fat.
As far as i know, steroids just give you regeneration powers like wolverine so you can keep going and going, which doesnt help much if you've only got time for 3 workouts!
Also, the cardio might be stealing the calories you need to put on muscle! Dont forget to gain = calories in>calories out!
PLease give this a go before you try steroids?
I think you'll be pleased!
Then if you still really wanna try it, theres a billion people in the anabolic steroids section that will help you out with how to do it safely, but i think if you asked them right now they'd ask you to try the other stuff first too