Our most recent project was to build a custom magento plugin for tax calculation service and also integrate it with one of the biggest payment gateways (First Data). We have been retained as this company's worldwide service partner.
The update and upgrade tasks are usually straightforward but a lot depends on how many versions we are jumping, and this applies to Magento and also modules. In May we finished a project that required two version jumps in Magento, a cleanup of severe data corruption across two databases, and outdated plugins.
You would work with Magento Plus Certified developer, our rates are competitive and we have immediate availability to help with the imminent launch of online printing service.
I'd be happy to discuss this at your convenience.