There aren't a whole lot of tandem inflatable kayaks that can carry enough gear for 2 (I am assuming you are taking another along with you) plus 2 passengers, but they do exist - but they are hard to find under $1K. You need to decide what sort of conditions you will be using this boat in: white water, flat water, or mix of both.
The AIRE Super Lynx will easily do what you are asking, but the price tag is higher than $1000. These can handle some milder white water, as well as function quite well on flat water. Be aware that you can get one 20% off an '09 Super Lynx right now as they are having end of year clearance to get rid of the remaining stock of '09's and make room for the '10's. $1199 is a smokin deal on an new SL, they are typically $1500. Check them out at The Boat People:
Used Whitewater Boats And Accessories
AIRE also makes an Inflatable Canoe (the Traveler) which will hold even more gear than the Super Lynx, but is not as streamlined.
SOAR makes a nice inflatable canoe as well that can hold a ton of gear as is very well-respected, but they are pricey as well.
I would tell you to watch for a good used AIRE product, or bite the bullet and get a discounted Super Lynx right now - they hold their value very well.