Write some software -- 2

we are using erpnext platform (erpsoftware). we need few changes in the platform. we need to chnage the bill letter head ( need to add company name and address ). alos we need sort products by alphabetic order. please bid only if you know erpnext platform and plz don't bid for min amount and ask for more money. and we don't release payment before finishing the work. thank you.