I will speak for my gorgeous wife. She is a poster child for the g-bypass (3 yrs ago). Has done wonderfully (lost 140 lbs). And we cruise as much as we can. She has learned how much/little she can eat, so she does very well.
While everyone is a little different as to what they can tolerate after GB, she can do most everything...in moderation. And I will admit that when I want to take 'advantage' of her, I get her a frozen margarita....takes effect almost immediately! (just kidding)
You mentioned lap-band or gastric bypass (Roen-Y). The roen-y is the 'gold standard'. The lap band has issues that bear serious investigation before making that decision.
R had hers done in conjunction with a wonderful program in Lexington, Ky. Great pre-op and post-op support. Also you can check out... http://www.obesityhelp.com/ especially the forums.
Her quality of life is vastly improved...greater mobility, no blood pressure troubles, better sleep AND she now wears size 6-8 instead of....whoa...better stop there!!!