magento needed

Hi, I am looking for Magento Expert who can help fix our current site which is having issuses. I have listed the issues we are currently having. Please send me some magento examples you have created. Also, give me a price. - when one customer collect the items in their cart and wait to check out. then the quantity will be deducted immediately. so other customer cannot check out because of less quantity(they select same item at almost same time). - Can we change it so the quantity of an item is not deducted from the site until after we ship the order. - If someone waits more than 20 minutes to check out the site is timing out on them. Can we allow the site to not time out? - Here is ANOTHER Major issue we are now having. These are stopping us from receiving payments, and need addressed. I have received two orders from the site. I received payment in Paypal, and an order was emailed to me, BUT the order can not be found in Magneto?? This has happened twice in the past couple day. We have received more orders where we got the paypal invoice payment emailed to us, but the orders are not showing up in Magneto? Here are Magento Threads I found like ours. [login to view URL] [login to view URL] - I reviewed process again, and we can actually ship up to 1000 kg, not 100kg. Can you make the shipping reflect 1000kg? - Another customer is trying to checkout by using the bank transfer function BUT the site will not let them place the order because they are getting a undefined error. Please address these issues. Here is a article on the topic. [login to view URL] - Coupon and promotion not showing in check out.