We did a 5 day private tour that included Meteora and Delphi with Private Greece Tours. https://privategreecetours.com.
They are spectacularly good. We had George for a driver and he is my favorite of all the drivers we've ever used anywhere. He's not a licensed guide but Private Greece Tours will provide an actual guide as well for an additional fee. We didn't want that. George talked with us about sites as we drove and approached and then turned us loose and waited nearby. That worked out well for our particular touring style.
Meteora is awesome. We loved it there.
Here's some TripAdvisor reviews of our tour pasted below. If you want to read more, go to my profile on this site and you'll see a link to my travel blog, where I wrote about our Greece trip at length.
We did tour the Delphi Museum. It was worth it, I guess, but I'm not a museum person. I have the attention span of a preschooler, I think. I wandered through in about 20 minutes but my partner stayed longer and liked it.
https://www.tripadvisor.com/Attraction_Review-g189400-d1924860-Reviews-Private_Greece_Tours-Athens_Attica.html
Seriously consider Private Greece Tours. It was not that pricey at all. I believe the cost was 1700 Euros, which we split between the two of us. If you're a group of 4 or more, the prices is so economical. But even for the two of us, we felt the value was worth it. We almost booked a big bus Gate 1 tour that was only about $100 cheaper and had hotels that were poorly rated. With our private tour, the hotels were lovely. We came across many Gate 1 48-seater buses as we drove around in our Mercedes van with George and we were so happy with our decision.