TC
Firstly is it possible your Bank or Credit Card Company are giving you free Travel Insurance that you are unaware of. Eg RBS Royalties Gold or the Lloyds TSB Platinum card holders get it free.
No matter what you do make sure you take a European Health Insurance card with you.
See:- http://www.nhs.uk/nhsengland/Healthcareabroad/pages/Healthcareabroad.aspx
As far as Travel Insurances go start with the two caravan clubs, and then try your own domestic home and car insurers to see what they have to offer.
Then you can surf the net!
Most important of all is that you fully notify the Insurer of absolutely every illness , problem or operation you have had in ???? years. They will tell you how far back you need go.You can check with your doctor. Tell them about every single drug you take.
Why ? You may ask.
Unfortunately over the last few years many a travel insurer has sort to reject a claim on the grounds of non disclosure of a material fact saying the illness on holiday arose because of , say a splinter, that wasn't notified to them prior to your holiday or inception of the policy.
make sure amongst everything else that full repatriation is covered in the event one of you falls ill.
Lastly check with your household insurers that your home cover wil continue for the full 6 weeks you are away. I assume the home will "technically" be unoccupied? Most Insurers only allow 4 weeks unless special arrangements are made.
That's plenty for you to sort out. Good luck.
Cheers
Dustydog