I had a flick through this thread and agree to a point.
Most stuff in the uk can be ridden on what you want 160 to 180 ish travel. However most of that is true if you know how to ride and know the lines and the speed you need. For most stuff in the UK now I will use my Nomad, and I am selling my down hill bike because I am just not going to use it enough now.
However for the last 3 years I have ridden that bike (40s on the front and 200+ at the back) all over the place and loved it, it has been a massive aid in my progression. If all you want to ride is danbury then 160 will be more than enough, however if you want to go for the bigger stuff at Herts, Chickie or Woburn then a bigger bike can really help with learning - have you ridden a bike with Fox 40s on - they give you a certain confidence? A good big bike well set up for your weight will feel prety nimble but will also give you a bit of get out of jail travel for all the times you case or overshoot the landings. As an example I would happily throw my down hill bike around the pump line and the dirt jumps at herts.
I would make sure you have visited the places you want to ride (and progress to) and then decide what bike you need to learn it ( I would suggest a visit to Woburn and Aston Hill for sure if you havent been already as they are very different to Danbury which you may love or hate). I bought my big heavy down hill bike to learn and progress on so that I was able to look at something and never have to think " I dont really have the bike to run this" and it did that brilliantly for me. Even the guys at Herts spend a number of years on Demo's before moving the bottle rockets.
What ever you end up getting - decent geo and a bit of bounce will put a smile on your face for sure.
If I were in your shoes I would seriously look at a Voltage which can go 140-180 on the back and take anything from a 140 to double crown fork on the front, sorted geo and playful size. They pretty light and chuckable but also take the big stuff. They have also been around long enough for a load of good buys on Ebay. Here's 2 examples
Built up for play
http://www.ebay.co.uk/itm/Scott-Voltage ... 416e869655Built up for a bit more aggro
http://www.ebay.co.uk/itm/Scott-Voltage ... 23257cb7b9