Hi, I am an OpenCart expert and I can do this job for you. I will design and build your store, setup custom invoice with logo, reset invoice number to 1100 and all other requirements you have mentioned. Also, I can set up few other things for you in this like excel sheet uploading of products which will benefit in future updating of inventory with ease. Also, I will personally enable SEO URL for all the products with matching meta keywords and met tags so that your site will rank good with Google and other search engines. Your choice of OpenCart is excellent as it is the lightest ecommerce platform and performs exceptionally well. I do not want to ask many questions as it will b part of development and once in development, you and me will have many questions, answers for which, have to be found. ALSO, I have much more to share with you. Please check PMB.