Install 2check.com shopping cart

1)I'm looking for someone to remove Paypal as a payment method on my website and install a [login to view URL] cart instead. 2)I also would like this same person to create a custom error page for me that provides the user with detailed MS Access error messages (with BACK button)for all the common error types. 3)The last error I need corrected is when a user trys to upload too large of a file when placing their home listing on our site, the site crashes. It's written in ASP and seems to timeout after 20 seconds.