Magento, fixing little problems and optimizing a site

I need to fix my Magento site.. there are some bugs in the CART/CHECKOUT procedure. SUBTOTAL in MYCART displays ZERO instead of sum of item price. After that, in SHOPPING CART & CHECKOUT, SUBTOTAL stilll is wrong and, if payment is done with TAX (European clients) calculation is wrong (TAX is not displayed). **Al I need a person that: 1) Is expert in Magento (not just generic programmer) 2) Is a freelance _(real!)_. Will work on the job himself and not pass it to a third person 3) Will be available on CHAT to work together 4) Speaks, reads, writes in good english** **All these points are essential.. Please don't bid if you do not fullfill these requirements !!!!!**