if you do a search in Google for "Majorca 121" there's a web site called mallorca-restaurants-121, do a search on their site for restaurants in the Manacor region ( there's a handy map to click on ) and it lists some top rated restaurants in the Cala D'or region including a Michelin starred place in Sant Llorenc which is reachable by Taxi.

Personally I don't think you can go wrong with Port Petit which overlooks the Cala D'or harbour area or Can Tromp in the centre of town.

As for trips to Soller I'm sure either you're rep if you're using a travel company can sort one out or there are other various coach trips available through currency exchange shops, alternatively if you drive car hire is fairly cheap and its a nice drive.

Have a great time (we're going in September as well so maybe we'll pass unknowingly in the street )

I would thoroughly agree with the Can Trompe recommendation - lovely restaurant in a great location serving great Mallorquian food and seafood. In my opinion, Port Petit is too expensive and too pretentious. I will be in Cala Dor for my wedding anniversary this year as always, and I want to go to Porto Colom, which is just a few miles outside Cala Dor and has the most lovely restaurants on the waterfront. If you have been in Cala Dor then it would be a lovely surprise to have a taxi pull up an take you to Restaruant Florian in Porto Colom for the most lovely food in a relatively unspoiled location. Have a walk along the seafront and perhaps a drink before dinner, and I guarantee you will thoroughly enjoy your evening in this beautiful spot.
Have a look at this website.
http://www.skybluemallorca.com/public/382.cfm