You have your heart set on doing it all in a felouka? You know there are no bathrooms on a felouka, right? It's roughing it all the way...which is fine for some people, so long as you know.
I'm not real sure how long it takes from Aswan to Luxor (going with the river -it's faster) but it would have to be 2 or 3 days I think. And, yes, there are some good temples to stop and see along the way. Kom Ombo and Edfu for sure. They may let you out at Esna and make you take a microbus on into Luxor from there rather than negotiate the locks. I really don't know.... surely someone here is a backpacker and can answer these questions. If not, go to the Lonely Planet site and ask the question on the Thorn Tree under Africa. There are mostly backpacker types looking at that site.
Debbie is right in what she is saying, Felucca would be roughing it and could take ages depending on the wind strength.
You can either got to Aswan from Luxor by Cruise which is about three days. You would usually stop at Esna, Edfu and then on to Aswan where you can see the Philae Temple, Botanical gardens and the Dam etc. The Nubian Museum is definately worth a visit by the way as is the market which I think is fantastic. You could then get the first class train back to Luxor which takes about three hours. The trains are really nice and comfortable . If you are not really bothered about the sites between Luxor and Aswan you could simple take a train from Luxor-Aswan and then back to Aswan again.