The guy who said you need to get big to lift heavy weight was full of shit, there are plenty of people, man or woman who have lifted heavy shit while having a light body weight.
The techniques are a bit different because powerlifters and bodybuilders have different goals. Strength versus looks. A big differance is plers use more compound lifts to hit multiple muscle groups to increase strength and pl numbers, and bbers train more muscles individually to make them larger regardless of strength.
I wouldn't worry about bench shirts or suits, even if you did compete in a meet you don't have to use them.
I don't know enough to comment about 5x5, or 3x3 because I don't have personal experience with them, but have heard of good results from them. I would still recommend 5/3/1 because it gives you an option to use accessory work that promotes hypertrophy but still focuses on strength increasing.
Hope this helped.