Magento trade multi-address delivery drop ship site upgrades

We have a trade only website running Magento. Currently, we have a 100 item catalogue password restricted for B2B buyers only. It's a 2-type website; 1) Order items for shipping directly to your store. 2) Order items for shipping directly to your individual customers. The first stage works OK. The second stage has our current developer stuck. At the moment, it's possible to order multiple items, and ship to different addresses, but the stages have some annoying bugs. Most problematic bug at the moment is that upon ordering a second item the same as is already in the cart, the delivery address reverts to the 'new' delivery address for both items, and increases the QTY in the cart to 2, rather than putting a new item in the cart with the new address. Apart from this bug, the site works properly. We need an expert with a high level of experience to; Either use existing code and iron out the bugs. OR (preferred) Start again with the following spec; Trade customer should open a sub-order, enter a name/address/tel for the first drop-ship order, along with the first item to dispatch. Then either add more items from the cart, or via the site catalogue, to ship to the same customer if required. Once first order is completed, start a new sub-order, add a second customer name/address and repeat. You should end up with a shopping cart that's split in to multiple sub-carts, with individual name/address/tel, order details, and shipping costs for each sub-order. Shipping is calculated at a fixed price per 30Kg of goods ordered. Cost is also calculated on delivery postcode area, this is fully working functionality at the moment. When all orders have been placed, the trader can checkout as normal, paying for all orders together in one 'master' shopping cart. Orders are then split to individual orders and passed to our warehouse admin for processing. This is 95% working already, but needs an expert to take a look at this with a fresh pair of eyes. It is not straightforward, and not an easy project, so please only apply if you are very experienced with Magento. We also require the shipping zones to be upgraded to shipping to multiple countries in Europe (selectable), this should be an easy upgrade. Paypal standard needs to be integrated and tested. Sagepay needs to be integrated and tested. --------------------------------------------------- Future upgrades on the same site are for payments in another currency, and multi-country/multi-language support. This will be offered if the first stage of development is successful. If you want to see the site and test current front end functions, please PM and I will send the domain and a login/password.