What's the actual gauge on your pattern? You could probably substitute a lot of different yarns if it is a pretty standard gauge (like 18 st/ 4in). You could even use a regular worsted yarn and use bigger needles to get the gauge. You could definitely hold two yarns together to get gauge as well....it would just take some experimenting.
Ariann Cardigan in Brown Sheep Cotton Fleece - 11 inches and two buttonholes done!
Tomato from No Sheep for You in Cotton Ease - nearly done! One sleeve left.
Tuscany from NSFY in Elsebeth Lavold Silky Wool - it's working up beautifully.
Montego Bay Scarf from Summer 07 IK Knits in Sea Silk - an indulgent knit