Small nopcommerce v 2.50 customization

I need a small customization of nopcommerce 2.50 e-commerce solution. We are using nopcommerce 2.50 with a template. I am looking for someone with nopcommerce experience who can develop and implement: 1. In Admin/Orders view I need new button to print selected PDF invoices. User can select invoices and by pressing "Print Selected" selected PDF invoices should be generated for all selected invoices. The invoices must be printed in user language - the language of the current user ! 2. Customize PDF invoice layout - change text from Order# to Invoice # ( custom text ) - print VAT table - we are using single VAT 20% and currently on the invoice it is printed Tax 20% and tax total. We want to print table where will be printed on one line fixed text VAT 20% , order total excluding VAT, order VAT total ( this field is currently printed - tax total ) - when printing invoice from admin area - we need the invoice to be printed in currently logged user language 3. If possible, I would like to have a possibility of mass entry of shipment numbers. This view should display orders with a possibility to filter only orders without a shipment, filter by order # and date and the user should have a possibility to enter shipment numbers in column - similar like product variant mass change. This modification must work 100% like manually entering shipment number from the order detail - i.e. register shipment number, change order status, send e-mail to customer... 4. Admin/Orders - I would like to have Export to Excel by filter - orders between dates, Orders with status not delivered - all current filters. 5. After upgrade to nopcommerce 2.70 I want to upgrade also this customization to the latest nopcommerce version.