-- Last Updated: Sep-20-12 10:02 AM EST --
I think you are proabably posting this as a hypothetical informational challenge rather than actually planning to plop newbies in Force 5 winds so I will treat it as such (and avoid lectures on the dangers of big water and novices.)
You are likely looking in the $1000 to $1500 range with high sales volume RM boats like the WS Tsunami family or the similarly priced Venture Easky or Perception Carolina lines(exact model/length for each would depend on the approximate size range of your projected paddling buddies) .
Personally, I'm a fan of the Easkys' sort of hybrid Brit/Greenland styling for "bang for the buck" and for confident handling in rough water, though I admit I have never had mine in conditions as severe as you describe. But I have heard feedback from others who own an Easky and report using the model in challenging Pacific coastal conditions. The only drawback I would see to the Ventures in conditions is the vulnerable rubber hatch covers. I would add a deck mounted security strap across each one if I was going to take it in conditions where a cover could possibly be wrenched off. Lack of a day hatch is annoying but you are talking about a basic good value, not all bells and whistles.
Most of our local dealers have these models on sale this time of year for 10% to 20% off (I scored mine 2 years ago for 30% off).
Of course the absolute cheapest would be to build your own Yost boat or traditional wood and nylon/urethane skin on frame. But if you did that you would probably love it too much to loan it.