Any 3d modeller that can export .obj format would do. As long as you're comfortable with it. If you're looking for free modellers google wings3d (easy to learn), anim8or and blender (difficult to learn but considered very versitile and powerfull). These are totally free and can export .obj format. Also google uvmapper for texture templates. uvmappers comes in a free 'classic' version and a paid pro version.

DAZ3d is currently giving away Hexagon for free. This is a nice modeller for which you can find clothes making tutorials on YouTube. But you got to hurry before they end the deal which was supposed to end months ago but they kept extending the deal (which is not likely to last much longer).

Hope this helps.