Website Updates

Hello, E-Commerce website has just recently had a major set of improvements done but just before project completion, there arose several bugs that did not get fixed and therefore must be fixed before this version can be released. 1. I want someone to do a code review of this version. I am looking for sage advice from someone who has a lot of experience in website optimization. 2. When the customer checks out with PayPal, the selected inventory items do no decrement properly. This should be a minor problem to fix. 3. The shipping calculator does not work properly. It must be very sophisticated to automatically select the appropriate methods of shipping to offer the customer based on the weight, cost, and ship to location. Currently the customer can create a 400lb shipment and the calculator will offer them an envelope option which makes no sense. I am looking for a high level expert who understands and has a lot of experience in setting up shipping calculators for USPS and UPS both. I will provide cPanel and FTP login details to winner. This project is very simple, so please reasonable bids not more than $100 and serious only programmers need to place bids. I will submit 25% in escrow of total value to start, 25% will be escrow at the time of 25% work done and rest of the 50% payment will be submitted in escrow at the time of 50% work done and 100% will be released after the successful completion of project, please NOTE: I will not release escrow before completion and you have to make changes to our own server. Please don't bid if you are not comfortable with our terms and please reed attached doc file carefully before bidding. I will select programmer as soon I will find reasonable bid and good provider to do the job and need the modifications done fast. I will provide doc file with more details in PMB. Good luck!