You may want to look up sites like http://www.brilliantlighting.com/kits/monorail-lighting-kits.htm or http://www.brilliantlighting.com/mfg/track-lighting-pendants.htm Typically manufacturers like WAC, Prima Lighting will supply both the track and pendants. Whether they work properly is dependent on The rated voltage (eg- 120, 12, 24, ...) for the system as both the bulb and wiring for the track and pendants assume a particular voltage. If you decide on a low voltage system, there is a transformer that has to be purchased as well.

An ELV dimmer is the right type for the transformer on those fixtures. Sockets can go bad but jiggling the lamp around will usually flicker the lamp and tell you it's a bad socket. Transformers don't like heat. The fixture is for 37 to 50 watt lamps so try the Philips or Sylvania IRC 35 watt in it.

They're not necessarily bigger. If you have a standard depth junction box (as opposed to a pancake box) the canopy looks pretty much the same as any other canopy. But different companies have different canopies. I've seen non low voltage canopies which are bigger than low voltage ones.

I have Tech Lighting low voltage pendants in my kitchen. There is absolutely no noise from the transformer. Tech lighting pendants are pricey but they are high quality. They have quite a few contemporary red pendants to choose from. Look at the link below. There is an option to filter by color. Click on the red box. If you find a pendant you like you have options for the type of system you want, the color, the finish (satin nickel, bronze etc.) and the type of lamp you want. Mine are mounted with a Free Jack 4" round flush canopy system (as opposed to a mono rail or cable). The Free Jack mounts to a standard 4" junction box with round plaster ring (provided by electrician). The electronic transformer is included and fits in junction box, so in other words its up in the ceiling.Here is an overall picture of my lights In this picture youcan see the 4 inch round canopy. The transformer is up in there. Low voltage pendants