i have a lump on my achilles - only painful if i press on it. Was advised by physio in August to tape for each run, do at least 50 calf raises/heel drops a day and stop running if i feel any pain. Managed to do the stour valley path 100km race a couple of weeks later with no issues. Am currently training for Brighton - must admit i don't tend to do intervals any more as i find that the lump ends up getting bigger if i do so i just stick with mid distance tempo runs instead which seem to be ok.
I use this site (albeit not as frequently as I used to) and I ran this as my one and only (successful if slow at 13.5 hrs) attempt at a 100k event. I wholeheartedly agree with Russ55. This race is fantastic.... gorgeous scenery (particularly in the 2nd half of the race), fantastic aid stations and just generally a really well organised, great value for money, race. i was so impressed I've volunteered to help out next year even though I live about an hour and a halfs drive away
Personally, i'd go for the SVP100. Whilst not as big as the race to the stones, it's no where near as expensive. i ran it this year and found it to be one of the best organised events i've ever done. the route was well marked (and very scenic) with the added bonus of having no major hills to contend with, the aid stations were fantastic (didn't even have to fill my water bottle, they did everything for me) and there was always someone to chat with on the route
would agree with Ala1n, the SVP100 is a fantastic race. There seemed to be quite a few peeps there this year doing it as their first ultra (was only my 3rd but found it easier than a 35 miler i'd done in june) - 100km is an achievable distance especially with a year to train - i'd definately go for this one (though if you do get your accomodation sorted out asap as things book up really fast round Newmarket way)
Can i too just say how much i enjoyed the race Matt - was brilliantly organised and didn't need to get a map out once it had been marked up so well . Think the distance was maybe a couple of miles too far for me so will stick with slightly shorter stuff in future but would be more than happy to help out on CP1 next year if i'm needed (live in Northants so not just round the corner but think it's important to support fab races like yours). Hope to make it down for the marathon distance next year if it's on - it really is a gorgeous route to run!