Build new ecommerce site

I am looking to build a Seasonal Gift oriented eCommerce site in 2 phases: 1. Retail web site 2. Add wholesale to this I'd like bids for each phase separate and combined. The bids should include training. The site must be built using an existing eCommerce platform that is well recognized in the market with thousands of active sites such as Shopify or BigCommerce. The platform should have a good rating on easy of maintenance and the level of technical knowledge required to maintain it. It should have externally recognized SEO capabilities as well as OOTB templates and security. It should support all major internet browsers as well as mobile devices. The site will need to be able to send orders without manual intervention to Quickbooks and to receive notifications of shipping back. Given existing volumes, the site can be brought into production without this, but the quote will need to include this capability. If there is not the ability to link directly QB, then it must be able to call a SOAP service. During any one month, we sell 150-250 different items. We have over 2000 individual SKU's. We are a small business, so expect both the number of visits as well as orders to be relatively small. If you have a standard small business "starter package" that you offer, please send me this to start. I would like to know the number of implementations that you already have along with the quote. I will share a more detailed description with the top 1-3 bidders as well as performed a more detailed review of the platform of their choice. The goal is to get this project started within the next 3 weeks and to have a first phase live in 1-2 months.