Ok, I've done something about the holiday! Having purchased a copy of Lonely Planet (Wales), Emma and I reckon that the best thing to do accomodation-wise is to rent a cottage for the week. Looks like roughly £400 for a cottage for the week, which is about the same price per person as youth hostelling (possibly cheaper).

Found a website of Pembrokshire coastal cottages: http://www.coastalcottages.co.uk, and there are plenty available for the week we're looking at. [That's the week starting Monday 5th July Nick!]
The area around Haverfordwest looks a good spot. This is the largest town in the area (good for shopping, etc), and is central(ish) to the coast.

What do you guys reckon? Are the price, idea, location, etc suitable for you all? Please also have a look at the site (if the link works :)); Emma wants to stay in the one with the open fire...