will keep my eyes open for a 300 then

- am happy enough playing with spanners but I cant weld so dont want too much rust
is auto or manual a better choice? - I have never driven an auto before but I understand they are more thirsty?
And are there any good lanes in South Wales? (got to ask since you are in Cardiff

)
If like me you are not up to welding, please do look VERY carefully as Discos are, without doubt, prone to rust.
We have two, a Tdi 200 manual and a Tdi300 auto. So, as to the question of auto versus manual; like most things in life - it depends!!
If you spend lots of time in towns in traffic, the auto makes life easier. However they ARE slower off the mark, once up to speed they're about same.
The manual will be slightly more economical than the auto, depending on how they're both driven. I find the auto, in particular, benefits from sympathic driving at lower speeds. Once up to 52mph, the Torque converter locks up so then it runs like a manual, in terms of fuel efficiency.
Whether it's manual or auto, the key to a happy Disco life is finding an example which is rust free (??!!) and with a good, documented service history.
I bought one last December, '98 Disco Tdi 300 auto, 77,000 miles and I'm delighted with it.
Almost no rust and an excellent service history.
Hope this helps,
Dave