Originally Posted by wilfskins
we are taking full camping equipment and aim to be relativley self sufficient for a journey lasting 8 days and covering aprox 550 miles.
Hi, and welcome to the forum!
I will say that 8 days/550 miles might be a bit ambitious for a newbie loaded tourer. I don't know what kind of shape you're in, so I could be putting my foot in, but I know that the SF-LA AIDS Ride, supported, has a similar time/distance rate, and it is very challenging to some people. I'd say you could possibly put in 50-ish miles in the first few days, but then you would need to ramp up to catch up, and could be putting in 100 miles/day the last two days. Extreme, especially considering terrain/mishaps/breakdowns. I would suggest you train, loading your bike before you go so it can be "optimized" before your trip, as well as for getting you in shape. If possible, I suggest you give yourself more time to cover the 550 miles, just in case.
Also, if you are an experienced tourer, I apologize in advance.