Julie - Choice of three in the Manchester area:
Running Bear on the main high street in Alderley Edge,just near station.Very good service and choice,especially off-road.
Up and Running,towards the top of Market Street in Hyde,just off the M67.Huge choice,with podiatrist and treadmill to make sure you get the right shoes.
Personal Best in Chadderton,just opposite Asda petrol station.Smaller shop but very helpful and knowledgeable staff.
Any of those three would help you out,no problems.Good luck....