Window Shopping for Wedding Dresses

My fiance and I have been together for over three years and have never really discussed marriage before the proposal.  We had both joked and hinted, but never a serious a discussion.  So, needless to say, we have a lot to talk about.  The first thing I wanted to know was what kind of time frame he was thinking....tomorrow, a year, three years?  We talked about it and agreed that at this stage in our relationship and our lives, we do not need a long drawn out engagement and are throwing around the idea of September or October.  Now for the next basic issue, where?  I am 110% sure I do not want a big hoopla of a wedding.  I would really love to go to Vegas and just have a simple, fun, romatic Vegas wedding, just the two of us.  On the other hand, I would feel guilty if the boys (his and mine) aren't included, and I would like them to be there.  I'm torn between the right thing and the exciting thing.

I have been having a little fun looking at dresses and was thinking if we do Vegas a dress in this style would be fun, but a dress like this would require a lot more push-ups, a lot.  My mother will die a million deaths if I wear a white ball gown!  LOL