I'd Like To "Ask The Audience" Please: It's A Celebration Situation!

I've been going back and forth about this for a while, so I thought I'd bring it to the blogosphere and see what everyone else thinks.  The girls birthdays are in October, November, and December.  Last year only Holly got a big party because it was her 1st birthday (and that's a pretty special day!), but this year we're having a combined party for all three girls in early November for our family and close friends.  We chose to go this route because inviting people over three months in a row for a party sounds a little excessive.  I know some people choose to only let one kid have a party each year in rotating fashion, but I got a party every year so I'd like to do the same for them (and besides, let's face it, I live to throw parties :).

Mud Pie Cupcake Birthday Hat

I have some questions about birthday etiquette and I'd love your thoughts.

Friends:
Do we invite the girls' little friends to this party, which will be on a Saturday late afternoon, or plan separate, more casual get-togethers for their friends closer to their actual birthdays?  We have a lot of family close, so inviting only our closest friends and family still adds up to nearly 50 people (if everyone came, which they won't).  Tacking on additional kids' friends to this list boggles my mind--we simply don't have room for it.   However, the thought of this big party plus at least two little party-type-occasions is also mind-boggling. 

Gifts:
We want people to come celebrate birthdays with us, but if I got an invite to a party for three children, I'd feel obligated to bring three gifts and would probably feel burdened by this, given the current economic climate and the season of life we're in.  I don't want anyone to feel burdened!  So should I say "No Gifts Please"?  If I got an invitation to a kid's birthday that said "No Gifts" I'd bring one anyway.  Should the invite perhaps say "Gifts Optional"?  Well, really, gifts are always optional, so that sounds sort of rude.  So what I've been thinkin' is that I'll include a little note that spells the whole thing out and goes something like this:

"We are so excited to have everyone come celebrate with us. We will provide drinks and dessert, come ready to have a great time! We realize that celebrating 3 children at once is a little unorthodox, but their birthdays are so close together that it seemed like the easiest way to do things. Please don't feel obligated to bring three gifts. They like all the same things and are happy to share a gift between them, and mostly they'll just be happy to see all of their favorite people in the same room. Hope to see you there!" 

Is it presumptuous to assume anyone would even consider bringing three gifts?  Is saying nothing at all the best thing to do?  Any thoughts or advice would be fabulous.

I did find a couple of great websites for party etiquette, listed below.

Hosting A Birthday Party: Proper Etiquette and FAQs

Children's Birthday Party Etiquette from ModernMom.com