For those of us living in the South East, I cannot recommend the above nursery enough. They're based just outside Hartfield, A.A.Milne country (the bridge where you play Pooh Sticks is only down the road!) and I would say they are the biggest stockists of herbaceous perennials in this part of the country. It's a proper nursery, no coffee shop or garden furniture in sight...just rows and rows and rows of plants. I bought several plants there last autumn and they did brilliantly, so went back today (even though it's 20 miles away) and stocked up! I also use their listings of plants as a useful guide as I find them accurate and concise. http://www.perryhillnurseries.co.uk/index.htm
I'd agree with you Aaron. They were the only nursery that had a Clerodendrum trichotomum that I wanted for a present a couple of years ago. Although I live nearly an hours drive away, it was worth the journey. Chris