
You can buy just the heads from MadeToMeasure, but they are quite pricey. I did a quick test to compare the US Golfsmith prices and Made to Measure, and the heads were £17 in the US, £31 in the UK. The shipping costs weren't that high imo (about £15).
The problem is that Golfsmith won't sell you the snakeyes stuff online and ship to Europe... there's a warning in the detail of each snakeyes component to this effect.