Hi,
i just want to say that i specially work on OsCommerce, CRE loaded, ZEN Cart as well as Joomla.
So far as customisation of OsCom modules in CRE Loaded is concerned, i can provide u a number of sites where i applied the same.
If u tell how many modules i have to customize, then i can exactally tell you the time taken.
Hope u can better judge. Thanks in advance.