Use http://www.skyscanner.com to find your flights. You dont need to fly out with the same airline you fly back with. They will find the cheapest in each direction not the cheapest return flight.

Several places offer rooms at competitive prices you will have to search each coz they vary at different times.

http://www.alpharooms.com

http://www.reserveahotelonline.com

http://www.go2spain.co.uk

are 3 decent ones

Make sure the hotel you choose is between the beach and the TF1 motorway or you will be forever climbing hills. Costa Adeje area around Fanabe and Torviscas is probably your best area with Los Cristianos a decent option too. Just not Playa de Las Americas which will likely put you too close to the areas you said you dont want

I would suggest the parque santiago 3 complex for you. It is right on the beach and there is a lovely long walk into los cristainos.

This end of tenerife is wheelchair friendly, i know as i push my friend round it every march.

There are also good bars in this area.

If you need any more info just ask.

We stay at the Dinastia complex very nice indeed. OK its a 15 minute stroll into Los Cristianos itself but it is lovely and quite in a evening if you want a quiet night in.

Also i am speaking from experience has we also have a special needs child, therefore we understand what your needs are.

i to am planning to go to tenerife next oct, i to would be taking my son who has autism, he doesnt like a very lively crowded place he doesnt mix with other kids so kids clubs are not important. but he loves the beach,so id like somewhere close to the beach (not hilly area) im diy holidaying as its just the two of us.ive found flights just need the place to stay, ive found pueblo torviscas has good reviews not sure what area is like, ( 1st time to tenerife)or would los cristanios be more suitable for us.
any help would be great, thanks