They ones are one piece. Suitable for bathrooms etc. a normal dimmer switch will do them. I can price them for you on monday for the halers ones in link. You no me, I'll don't want to make anything off you so I'll get the best trade price through my company and then let you know. If you want me to go ahead they will come with reciept and warranty.
The transformers are just for normal spots which I wouldn't recommend. They are cheap and nasty and not fire rated or splash proof like the above units