There are loads of châteaux you can visit in the Loire and the most popular ones are Chenonceau, Chambord, Cheverny, Azay-le-Rideau, Chaumont-sur-Loire, Villandy, Ussé, Chinon, Amboise, Loches, Langeais and Blois (maybe I'm forgetting one or two). Again, these are just the biggies. The châteaux you have chosen are fine if that's what you like. I might suggest at least stopping to see Chambord from the outside as it is one of the most magnificent looking châteaux you'll ever see from the outside. Inside is poorly decorated to not decorated at all but it does have the famous double revolution staircase designed by da Vinci and a visit to the roof top is pretty amazing too.
I'll agree with Sunshine's assessment of Amboise. I personally like the town but some find it too touristy for their tastes. Different strokes for different folks. There is one very nice restaurant in Amboise called l'Epicerie.
In regards to alternatives to Amboise there are many, many choices but other popular places would be Loches, Chinon or Blois. All are lovely towns with ample restaurants and cafés to choose from. Look at a map and see where these towns are in relation to where you want to go. To figure out drive times and distances from wherever you base to wherever you want to go (I assume you'll have a car) use the website www.viamichelin.com. The drive times assume normal traffic conditions and no stops and I find the drive times very accurate when these factors are accounted for.
If you need tips on what to see and do in the Loire then here are some of the major tourist office websites for the Loire:
The tourist office websites will list all the accommodation in their respective towns as well as the restaurants. You can also find out what to see and do in an area by looking at the tourist office websites.