HELP! Diamond buying?!

Hello,

I'm looking to buy a pair of Diamond Stud earrings for my partner for Christmas.

My budget isnt huge (around £300 or so), but I've never bought diamonds before and I'm not entirely sure where to look or what to look for.

I'm trying to really get the biggest carat weight and best clarity that I can for my money, set in either Platinum or White Gold.

The best I seem to be able to find are from The Jewellery Channel's 'Rhapsody' range. They are a total weight of 0.2 carat, platinum and VS clarity.

Does anyone have any ideas if they are a reliable website to buy from? Or does anyone have any other helpful information or recommendations?

Thanks a lot!