I see three ways of doing this using Google.

The first is to use a pre built Google custom engine. This would be the ideal choice as it should be done very easily, however the safe search option does not seem to persist well. http://test.leekiernan.co.uk/google

Google provides API access in two ways currently, however this is in the process of being moved to one RESTful protocol. This gives freedom on searching and allows full customisation of pages and advertising. The API allows 100 calls per day for free, and additional 1,000 requests cost $5.
http://test.leekiernan.co.uk/

The final way would be to bootstrap onto Google's own results. To present this well would be most challenging, as results are returned as a full HTML page and would need to be parsed and displayed appropriately. Further, this could easily be against Google's terms of service and would take by far the most time.