Being short but a little bigger (5'6", 34"waist, 27-28" inseam) I can certainly relate. I have dounf that military BDUs comes in a variety of sizes. They come in a variety of sizes (Xsmall - 3Xlarge) and lengths (short, regular, long although short is hard to come by so I hem a regular). Propper and Tru-Spec make BDUs to military specs, meaning you can get the size varieties. There are many military style BDUs also that are not necessarily made to military specs. Ripstop 100% cotton, 60/40 cotton/poly, and 50/50 cotton/nylon blends are available. Prices usually run from $20-$40 per pair, $35 most common. It might worth looking into.

Tru-Spec size guide
http://www.georgia-outfitters.com/dts.shtml


Propper size guide
http://www.galaxyarmynavy.com/size_chart.asp
http://www.botachtactical.com/propbdu4pocc6.html