80 miles away you'll only get Approach easily, unless you are on a hill.
Check NATS site for en-route freqs, but it's not very user-friendly:http://www.nats-uk.ead-it.com/public/in ... id=11.html
ENR 2.1 is the most useful
ATC transmitters at Green Lowther hill:
135.525 AMn "135.53"
135.85 AMn "135.855"
460.15 FM Ground UHF
Airwave TETRA for Annan — site 'DAG024O'
(Site is 1.3 miles away, bearing 327º from town centre)
393.6875 / 383.6875 TMO:142
394.1375 / 384.1375 TMO:160
Encrypted so no audio, but at least you can notice any nearby activity if monitor the 380-384 input channels
Kirkudbright Range said to be around 444 MHz
Air to air refuelling area 13 (AARA13) (IOM/Cumbria)
I wouldn't spend money on personal guides, not convinced they are much use, nor up to date.
Play around with OFCOM's WTR for local business frequencies:http://spectruminfo.ofcom.org.uk/spectrumInfo/licences