In reply to alexgoodey: I'd echo what Rab says above. Get up high and camp out. Good for the logbook and it makes so much more sense logistically.
Cairngorms are the obvious choice for overnight trips (the bothies here are very good too), should tick all your nav boxes if the clag comes in. There's really nothing else quite like the area in the British Isles. If you're really not into camping can you take a bike? Estate tracks are a fantastic way to get the miles in on approach to the more remote hills.
For contrast nip along the A86 to Lochaber for the pointier experience.
I'd also say try and get out on your own for a bit. I find I get more done that way and it's good to be responsible for the consequences of your actions. It can help inform decision making processes when leading groups in the hills.