Since I just stumbled upon this page, I figure I'll throw in my $0.02. I just got my first bike this year, and did a lot of the same research as I am a 6' 315lb fatty, and was worried about not getting a big enough bike to start on. I ended up finding a great deal on a 2007 Vstar 650 classic. After reading a lot of sites, I commonly seen the same ol "oh man that is going to be too small for someone of your girth, you better step up to a 950 or larger". What a load of bull. I have ridden over 8000 miles on my 650 the last year alone, and not once did I feel like it was too little for me. I have quite a few highway miles on it at 90mph+ and while it may take a bit longer to get there (which really isn't that long) it maintains it easily.
As for ergonomics, at first I felt like it was a little cramped, but again, it was my first bike so I really didn't know what to expect. With the bars mine has, I think they're drags, not sure, it kinda has a squatter position, which I find to be extremely comfortable, having my legs at almost a 90º bend with my calfs almost straight vertical. I have thrown this bike around and thoroughly enjoy leaning it to it's limits as much as possible.. my scarred floorboards will attest to that, and not once have I felt it's not enough.
If I was planning on riding 2up, which I really don't see in the near future, I would probably move on to something a bit bigger, simply for the extra acceleration. But I'm sure it would still be fine, just be a bit slower off the line. As it is, riding solo, I still pull away hard from any 4 wheel vehicle out there and honestly have no complaints about the bike.
So if you're looking for a first bike, want something fairly cheap and ultra reliable, and decide on the cruiser look, it's hard to go wrong with the 650 star. Being shaft drive, there's no real maintenance aside from checking your gear oil every now n then, the motors are super reliable and rarely need more than basic stuff like occassional carb sync, air filter, plugs, and oil changes. Run some seafoam or B-12 through it every couple tankfuls and you'll have a nice long lasting ride you don't need to think much about.