Create magento ecommerce store

The project is to convert an existing e-commerce website with 300 products into a site using the Magento platform. The design of the website will be based on the current website design. The new website is required as a minimum to have the same functionality as the current website. This project would suit a very experienced software development company who have significant experience in developing and implementing Magento based ecommerce sites, ideally in the UK and Europe. The site will need to have sagepay direct integration to take credit card payments on the site using the appropriate plugin. Preference will be given to a software company who can provide ongoing a monthly service for support/maintainance to the site. Please provide examples of companies (ideally UK based) to whom you provide this service currently together with an indication of the price that you charge on a monthly basis for support. The coding must be of the highest quality - please no ammendments to core code etc. Only companies who can supply reference sites that they have previously developed in Magento will be considered. All necessary plugins for the site will be paid by us, and will be in addition to your fee for developing and implementing the website. The site needs to be a very fast site, so for example Varnish / Litespeed full page caching will need to be implementing. The webserver used to host the site is a 16gb Xeon Dell server with SSD Raid 1 HDs. It will be a new server specifically built to run the new magento site with magento specific config i.e. NginX, Percona SQLUK, no control panel etc. Also they have Linux engineers 24 x 7 to assist with problems. However experience configuring and setting up the dedicated server would be desirable. If you are interested in this project please submit a PM with a list of your previous magento e-commerce sites, plus examples of support costs. I will send you the current website by return to those bidders who achieve the desired standard. I am happy for final bids to be adjusted once you fully understand the scope of the work involved, so please don't feel the need to low bid initially to get my interest. I am at this stage focused on choosing the highest quality development company, not the cheapest.