Magento configurable products Stock quantity

I am a long time user of oscommerce for over 5 years. I have opened another online store for t-shirts and am now using Magento. I am looking for someone who knows the best way to make Magento functionality that best fits my store. I have inventory and I need you to help me set up my store with one or two mock items to make sure all further items will be configured the same. I will add items myself after the 2 mock items are set up. I need configurable products so stock quantity can be deducted as items are purchased for each custom option such as t-shirt sizes. My shirts come in Sm, Md, Lg, XL, XXL. Some quantities are lower then others for different sizes. I need a contribution that will work so I can keep track of inventory. If a customer purchased the last XL t-shirt, I would like the option to purchase XL to stay on the site but give the customer a warning that this item is out of stock and will be on backorder once order is placed. This can be achieved by either a few red asteriks next to the XL, or a warning on the next page or shopping cart saying this item is out of stock. Can also have a star and maybe a link that says "what's this?" so customer can see why there is a star next to the item in the shopping cart. I am not sure which way is best so I will take suggestions as well as do research to see how other sites operate before bidding ends. I would like all this to be automated. My main concern is inventory. I need something to work like quickbooks. I realize Magento is powerful and can be used to track inventory, print invoices, etc but if you think quickbooks would be good to integrate then I may ask you to do so. Quickbooks keeps inventory but I still need Magento to have a backorder function/out of stock function for each custom option such as shirt sizes. I also need help to integrate 2checkout and make sure it works smoothly. I installed the 2checkout ins, all I need is help to set it up with my 2checkout and I will do a test order. Need to make sure customer is brought back to my store to receive their invoice and confirmation page. I also need a wholesale method set up so wholesale customers can log in and purchase items at lower wholesale price. I can sewt up the magento site and database myself. I just need you to make both stores pull from same quantity in database. Once wholesale customers sign up for an account, I have to review and approve their account before they can shop in wholesale section. Either you can have another database for the wholesale magento with separate design which I will make but I need both database to deduct inventory when customers or wholesale clients purchase a shirt. So they can be separate stores such as [login to view URL] and wholesale.bigtshirts.com. This is not my site just an example. But I need them both to pull same inventory. I can explain more details but if you do not already have ideas for this project as you are reading please do not bid and waste my time. I do not have time for you to post questions in forums asking the best way to do this job. I need you to already know the solutions as you are reading this project. I beleive in good communication and enough time to get the project done correctly. Summary: -Add contribution to configurable products for options to have stock quantity -Make sure 2checkout works. I installed 2checkout INS already. -Connect [login to view URL] to [login to view URL] so they can use same inventory. I will set up both stores and both databases with [login to view URL] just need you to make it work so I can sell retail and also sell to wholesale customers. Wholesale customers need to be able to purchase just one shirt if they choose. SO not sure if tier is going to work?