Hi, I have developed many ecommerce sites with magento 1.7,1.8 and 1.9 and completed upgrading and completed security patching job. because i have previous experience in this job you don't need to worry. i can complete the job in 3 days.
i can give a my client address in FL, USA to contact him for review. i have been working for him and done jobs like installing magento - theme , configuring, custom module development and database upgrade, error fixing etc...
Regards
Manoj