Should we just hookup with aviator, or this there a better way to do it?
you may get some good ideas from this thread from last year https://community.ricksteves.com/travel-forum/england/cotswold-day-trip
Viator, if that's what you mean, is a huge faceless advertiser and reseller of tours provided by others while taking a huge cut.
They run zero of their own tours, just stick up a website and cart the wheelbarrows of money to the bank.
Much better to find a good provider and go direct.
If you are looking for a guide, I always suggest choosing one from the British Guild of Tourist Guides, as they are all professionally certified to certain standards. https://britainsbestguides.org/ Some are driver-guides; some are guides only but partner with drivers.
I agree with Nigel and smay665. I have used Viator on a couple of occasions and do not think I ever will again. The tours were unsatisfactory, but live and learn, and read Rick Steve’s blog I guess. I am heading to England in October and I was not familiar with the Professional Tour Guide organization. Thanks for that.
Try the London Walks company. They have day trips to many places; the Cotswolds, Oxford, Cambridge, and more destinations.
https://www.walks.com/
You meet your guide at the train station, go to your destination. The guide is with you the whole time, giving interesting bits of information about what you're seeing; villages, churches, etc. and the guide rides the train back to London with you.
Another good idea would be a Rabbie's day tour on a small minibus with perhaps 4 to 12 people onboard:
https://www.rabbies.com/en/england-tours/from-london/day-tours/oxford-traditional-cotswold-villages-day-tour
These tours leave from the Victoria Station area.
A third suggestion would be to take an early morning train to Moreton-In-Marsh and meet up with this touring company: GoCotswolds. They give a really good tour in a minivan. The villages are listed here; there are two choices of routes through the Cotswolds villages:
https://www.gocotswolds.co.uk/
https://www.gocotswolds.co.uk/product/cotswolds-in-a-day/
https://www.gocotswolds.co.uk/product/secret-cotswolds/
Make reservations in advance. Their tours fill up quickly, so reserve as soon as you know your desired date.