I am very tempted by the DS. There are some downsides, though. I am worried about malabsoprtion. DSers have to take a LOT of Vitamins for the rest of their lives - like 20-30 pills a day. A big deal for some, not for others. You have to be very very diligent if you get a DS to ensure your proper nutrition. Labs must be drawn regularly that make sure your numbers are good, and adjustments made to Vitamin regimen as needed.
WIth the DS, the operation itself is very complicated, so it is very important to go to an experienced surgeon. DSfacts.com has a list of surgeons that are good. Most weight loss surgeons don't do the DS, so travel is needed for many patients to find a good DS surgeon.
It's a hard decision, I know. THe numbers for DS are very impressive. Honestly, if you are diabetic, then you should seriously consider the DS because it has a very high cure rate - like 98%. But with the DS comes a lot of responsibility and lifelong diligence to stay healthy. So if the vitamins and frequent blood tests would be a problem, then you are safer doing the sleeve. (Vitamins and blood tests are also important with the sleeve, of course, but not as immediately life or death critical as with the DS).
Also, keep in mind that the sleeve is part of the DS. Every DSer has a sleeve stomach - some are just a bit larger than sleeve-only patients, it depends on the surgeon. Some SMO patients have the DS done in two stages, with the sleeve first and the "switch" second. So you could always get the sleeve and then add the switch later if you find you haven't lost enough weight or resolved your diabetes. But doing it as two separate operations has downsides - you tend to not lose quite as much than if you had it all done at once. You have to have a top notch surgeon for what is basically a "revision" surgery. Scar tissue from your first surgery can make it more complicated. Also, if money is a concern, be aware that some insurance companies won't cover a revision surgery.
It sounds like you've already made the decision to go with the sleeve. But in case you are still debating, I wanted to add my two cents. Good luck with whatever operation you choose. It's a tough choice - but I'm sure you'll have success no matter what you decide is best for you!