I did the Roti-Bali trip about 7 years or so ago, wasnt kiting but surfing.
Roti is great very cool place, the main break is an awesome left hander, the wind if i remember came in every arvo as it would blow the waves out. there is a hugely strong rip that runs parrallel to the beach when the tide is in and kiting would probably be a pain. I think there was another beach round the corner that could have been good.
Sumba is a wild place, take some time out of the kiting/surfing just to have a look around. take plenty of "beetle nut" wherever you go the locals love it. Visiting villages is just the thing to do, take pens, pencils balls etc for the kids. South coast a place called Tarimbaing, real fast barraling right hander when it gets going. Very shallow, very powerful, very beautiful. Watch for sharks saw a few around here only little ones here though. Wind was in again every afternoon, as i remember having to get up early for surfing. Further out on the east coast is a place called Peno or Puno something like that. There are awesome waves, lefts and rights, beaches and a rivermouth here. Its famous for the market on the weekends there. Would be great in fact perfect for kiting....if the wind came in ....cant remember what the wind was like when i was there...good surf though and good fishing...take a rod.
Sumbawa, all the hype is true but its on this island that the crowds start to appear, go south coast, follow the surfers. Have a look around as well,
Lombok, stay in kuta on the south coast, nothing like its counterpart in bali. Dont know about the winds, though i seem to remember it was always windy as the surf was regulary blown out by early afternoon.
Have got heaps more info about travelling the other side of Roti, but dont want to put it here as i'll take up pages and pages.
Come to the Melville do on 26th May, 7pm, Legends Pub, hislop Rd, Attadale and i'll talk your head off about it. If you let me know in advance i'll bring a few photos to get you going.
I think one of the most important things here is dont get too caught up in the kiting/surfing thing stop and have a look around, the people are pretty cool, and if you go off the beaten track people are really curious about you and you can have some amazing experiences that you will probably never have again.
Ahhhh travel good for the soul.