Upgrade website

I have been trying for 6 months to get a reliable webmaster to make some additional script changes to my OS COMMERCE website. I have gone through 1 who after 2 months made no changes. Now another after 6 weeks made a couple changes on test site. We wanted this project finished 5 months ago. We need some scripts added to current site that will allow us to give groups seperate price, and able to make those set prices in each item. Also we want to add the ability to make changes to order after order is placed. Finally we would like to be able to offer qty purchase discount that will total weight, and prices. We know these scripts are available as our host has set up a test site placed the scripts on the test site. However after 6 weeks he has not finished everything, and been able for us to transfer our database to new scripts. Apparently he stated he had to start over, and add all scripts fresh on work site. But to transfer data would make our website inaccurate till we change all data for the new pricing. Which may take 3 or 4 days. Best case scenario is someone who could just add these scripts to current cart (according to him cannot be done). 2nd best scenario is ability to make changes to pricing on a work site, then when finished transfer the database, or scripts somehow. I expect this project to take approx. 10 hours max. We also are looking for reliable person for future needs for the website, and consultation if need. Bottom line we are looking for a value webmaster, not cheapest, nor most expensive. Someone who will complete job in reasonable time, do what they say, not cheat on time, can be understood verbally, and keep us informed.