Since you have lupus and fibro, I would suspect you have a good rheumatologist in your corner. If you don't, you must have some awesome PCP. I would first and foremost, have a discussion with the rheumatologist. If he/she is onboard with you having weight loss surgery, then you are good to go.
Second, you may want to reconsider the lap-band as your surgery of choice. You have autoimmune disease and you would be putting a foreign body in your body. Not the wisest choice. While I never wanted the lap band, I did some reading on it, and the manufacturer's literature specifically stated not to get a lap band if you had a history or family history of autoimmune disease. That said, the first surgeon I consulted with was more than willing to do a lap band on me as an "off-label" usage. Also, there are many people on these boards with lupus and other autoimmune diseases who have had the lap band and had no issues what-so-ever. Again, it's something to discuss with the doctors...first the rheumie, and then a surgeon. You might be better off with the sleeve or RNY. If you go for RNY, you won't be able to take NSAIDS or steroids. Disclaimer on that statement, I was told for a short period of time with the use of proton-pump inhibitors, it would be okay. The sleeve doesn't restrict your drugs. I would also recommend staying away from the DS surgery. There is a higher risk of kidney issues and you are already at risk for kidney issues due to the lupus (if you don't have kidney issues already). Speaking of kidney, if a nephrologist is already part of your medical team, you would want to consult him/her about the surgery as well. Actually, I would recommend consulting any specialist who is involved with your autoimmune issues about surgery.
I had RNY in May 2009. Before surgery, I lost 70 pounds. Since surgery I've lost 130-140-ish (I'm sort of stuck at the moment...and I would partially blame that on my lupus). Best thing I could have done for myself. Lately, I'm having issues with pain and fatigue...otherwise, I go to the gym religiously 5x/week, eat small portions, high protein, low carb, low fat, low calories, etc, etc, etc
I'm sure there is more I'm missing that I should mention, but I'm exhausted and not thinking well. If you have questions, feel free to ask.