Finally, remember that the lowest hourly rate won't necessarily mean the lowest overall cost.
Very true, you need to take into account any other mandatory costs which might include Flying Club Membership, Insurance and Landing Fees.
Some schools charge for landing fees, some don't, this can amount to a significant additional cost.
I could also go to Dundee or Cumbernauld but perth is the nearest.
There's also Fife Airport at Glenrothes, run by the same folks as the school at Dundee but more PPL/leisure focussed. Worth checking out if you are looking at the others