In reply to HarryPink:
Some reasonable sport on slate near Llanberis at the grades you mention.
Road Runner Crag, near Conwy, (on ukc database) has a selection of routes across the grades, tho I've not sampled their delights so can't comment on quality.
Also Castle Inn Quarry close by Colwyn Bay.
Routes on west face of Tryfan should work well for roped-up scrambling (eg Wrinkled Tower, Milestone Approach, Rowan Route, Notch Arete).
Also Tryfan Fach has a selection of easy routes (scrambles, mods, diffs) that might meet your requirements