help me plan a party! Help me surprise my wife :)

So before I was married - when I hosted it was simple - meat, grill, beer.  When I got married my wife took over some of the planning duties and civilized the events and I was the executing branch in that endevour.  Now that she's turning 40, I am planning to surprise her by throwing a small party for some friends BUT I'm a bit at a loss because I need to do it under the radar and that's hard since she's stay at home mom and I work out of the house  Also since she did most of the planning in the past I'm at a bit of a loss  So help me plan this and keep this fun  

I figure on 17 adults and 7 kids.  For birthday cake my wife wants this mousse cake but they don't make it in a bigger size...
www.portosbakery.com/content/mango-mousse-cake-9
So I figure I need something else.  I know she loves chocolate (the chocolate cheesecake from CheeseCake factory is one of her favourites) so I am thinking about getting also 

www.portosbakery.com/content/flourless-9

Since each feeds 10 to 12 people I figure small sizes of each or people get to choose and pick

I'm also thinking about getting 
www.portosbakery.com/content/potato-ball-tm-stuffed-potato-party-sized (50 pieces)
and a tray of veggies from Costco for appetizers along with Chips and Salsa.

Now for main course I'm looking to pickup hawaiian BBQ

thelofthawaii.com/catering.php

I figure 3 ohana sized main dishes (not sure which ones yet) and steamed white rice, bacon friend rice, BBQ Char Siu Chicken Fried Rice.  Also the next sized tray of steamed vegetables.

I might get some other frozen treats for the kiddies and big ones (eclairs and the like).  Might also BBQ some pineapple.

Appart from refreshments: thoughts?  I don't want to overbuy food cause I hate being stuck with it and I don't want to underbuy.....