Even if they do not release it, there are endless sources of models that you can customize to fit the bill.
I would say that someone on the dev team writing/playtesting/making official (even if not for tournies) rules for making custom characters would be the first step. that way, they could gauge whether or not to invest in making model kits or if they do, what direction and options are the best to do.
If all else fails and you dont want to do modeling or use other models, you could buy spare character models that you think looks cool and use the rules/points for whatever character is the closest to what you want the character to be. Then repaint and rename it .Just dont combine it with the actual character whose rules your using in the same list to avoid possible abuses.