Have you considered the SWCP.I completed the 630 mile Trail in 2 walks Minehead-Falmouth 2011 & Falmouth Pool 2012 each covering 3 weeks,but many complete in stages.It is a wonderful exploration of the South West Coast.You can find accommodation details including Camping, on the Nation Trail Website,South West Coast Path.Minehead- Lynmouth is quite dull,but enjoy the rest of the walk.Should i be of any further assistance contact keithburton81@yahoo.com

If you fancy a trip to Wales, the Pembrokeshire coastal path at 180 miles would certainly fit the bill. Plenty of camping opportunities, either wild camping (discretely) or camp sites on the route and you pass through loads of hamlets and villages for food/water etc.
Very beautifull as well:
http://nt.pcnpa.org.uk/website/sitefiles/nt_page.asp?PageID=2

Depending how far you want to walk each day, the Cotswold Way is a very nice 110-mile walk. This page here has useful information on where the campsites are and if the distances work for you, that might be an option (although possibly slightly too short for 2 weeks?)

In general, camping is a lot more expensive in the south than the north. Since moving down south I've noticed there are far fewer cheap and cheerful campsites than in the north - far too many are big sites catering for families, meaning you're paying for playgrounds and swimming pools you're unlikely to use.

One other option might be to join the Backpackers Club, which gets you access to their list of unofficial campsites and farms that allow camping along most of the long-distance paths in the UK. That makes camping feasible along almost all of them.

I'm an international member from Vancouver Island, British Columbia. I walked the C2C a couple of years ago, wild camping. Now I'd like to see something of southern Britain. It needs to be a path conducive to camping as I can't afford other accommodation. I would appreciate any ideas or hints.