Simple french links are legal but you have to be careful...for example a french link with a roller isn't legal. As long as you keep it simple (same metal used throughout, no moving pieces like a roller, smooth finish), you shouldn't have a problem. All of the bits you listed look ok.
Easiest way to measure for a bit is to
• measure a pre-existing bit, or
• run a string through your horses mouth. Leave about a quarter inch outside the mouth on each side and that should be your size. 4.5 inches is average.