Not that simple!!! MiL bought a super sexy 16x25w modern ceiling light and matching 2x25W wall lights. You have to buy a top quality dimmer, a top quality transformer (called a driver) and top quality LED that actually fits in the space within the light (check this carefully!).
I bought 2W LEDs from aliexpress that specifically stated were dimmable.
Here is a link:
http://www.aliexpress.com/snapshot/6037796230.html
They describe them as:
'Dimmable G4 24 leds 3014 chip led Silicon lamp 2W DC 12V 360 Degree non-polar' and mention lower down: "Dimmable: need Switching power supply DC 12v"

Then I sent them the Varilight who said they were the best LEDs they had ever seen. Tested them with their own V-Pro dimmer (which is really very clever indeed in that you can switch between trailing edge and leading edge and set min and max dim) and with their own drivers. All works very well. Note though that most combinations driver, dimmer and LED will not dim just 4W of LED indeed most state well over 10W as a minimum. This short para represents HOURS of my work so be nice! Good luck. Oh and don't by the TLC varilight dimmer it is not what it seems - had to return mine.
And here's the Forum thread not that it adds much.
http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11786&page=1#Item_11

I don't think the fitting will care about the voltage, if that's the only difference :)

As I said though the V-Pro dimmer does both types of dimming and will not be a cause of flicker. Also as I said most dimmers need 10 watts draw (and some a lot more) to be sure to work, so most likely you simply didn't match your dimmer with the appropriate type and size of LED - in the case I mention above V-Pro was used successfully to dim just 4 Watts but they tested the combination of my LED and their dimmer down to under 2 watts.

Dimming LEDs has to be approached as a whole system: for 12w fittings that is Dimmer, Driver and LED. It has been proven that a good LED will allow a dimmer to perform well outside its guaranteed limits.

Yeah its G9s, 240v system. Dimmers are in so I'd need to buy couple of LED G9s to try... Anyone recommend make and/or supplier...?

I actually bought some "G9 Crystal LED 3 Watt Dimmable Warm White Glass Ceramic 300° Illumination Energy Saving Halogen Light Bulb Halogen Replacement" they're not as warm as halogens but I prefer the light they give. Although they run such low wattage I had to add additional load to run the dimmer.

Posted By: andy-cheshireAlthough they run such low wattage I had to add additional load to run the dimmer.

Hadn't thought about that. How do I work out if that will be a problem (I'm using Varilight V-Pro dimmers and there'll be three lights), and how do I add load if there's not enough?

Edit: I think the Varilight dimmers require minimum load of 10W, so at 3W each it wouldn't be enough. So I presume best thing to do is simply find some 4W bulbs.

Edit 2: Got these:
https://www.amazon.co.uk/greenandco®-dimmable-replaces-25-35-Halogen-y/dp/B01E0365NS