Onestep checkout for magento

We want to get a price on make our own onestepcheckout module for magento. We basicly want just the same type as [login to view URL] offer. And we need it to be licensed based per domain, so it need to generate a licensecode for each installation. Basicly a working and good looking onestep checkout for magento. It is also important that it can be used for the payments and shipping methodes allready inside the store. And it should also need to dynamicly chnage prices etc when you change payment/shipping methods by settings set from the metods in admin. Etc.