Microadventuring, mini tours etc

I'm planning a 4-day solo mini-tour for the late May bank holiday. The only fixed element at the moment is visiting a mate in Malvern on the first night. Other requirements are finding nice roads to ride on, including riding up Cheddar Gorge, just cos I've never ridden up Cheddar Gorge before. And judicial use of trains at either end to avoid boring/busy bits closer to home.

So, something like:

• Day 1: train to Oxford, ride to Malvern (~60/70 miles)
  
• Day 2: Malvern to Chepstow, via Wye Valley and possibly Brecon Beacons (~90 miles)
  
• Day 3: Chepstow to Chippenham, via Cheddar Gorge (~90 miles)
  
• Day 4: Chippenham to Reading, train home from Reading (~60 miles)
  
  

Probably B&B'ing it the other two nights, so will be able to travel quite light. Intermediate locations based on a very rough Google Maps route sketch.
If anyone's got any route suggestions, either based on the above or different suggestions, would love to hear. (Especially if GPX files on ridewithgps!)