OSCommerce Mods

I need 4 OSCommerce mods developed or applied if they are already available: We use OSCommerce as an offline order system in our shop...therefore we need: 1- manual editing of prices at end checkout (could be complex). So at the final step staff need to be able to change the price of a product manually. 2- address can be bypassed and it will print a blank address box on the invoice so it can be written in later or address can be entered and it will print the address on the invoice 3 - shipping needs to have the option to be added at £12.95 / £6.95 / not at all per order 4 - when submitting the order the status should automatically go to processing and the PC should automatically print 2 copies of the invoice Please quote total price for all mods or the price per mod etc Thank you