I live in the Camborne/Redruth/Helston area – plenty of bridleways and cheeky footpaths available round here – good mix of XC and techy downhills as mentioned above. Give me a shout if you fancy hooking up for a ride!
Not too familiar with Penwith area riding-wise, did do a ride west of St Ives on my own a while back, just got the map out and put together a route over the moor which was nice so that would be an option. Otherwise, drop Gavtheoldskater a email as he’s down there and might be able to give you some route ideas?
Oh yeah…hope you have sea legs as the boat trip over from the Scillies is not nice when it’s rough!