What utilities can I use to simulate I/O load for a DB restore and DBCC check?
SQLIO is good for doing raw disk IO load testing, but a good way to simulate a comprehensive load testing is to use the SQL Profiler tool included with most sql server installations or using the SQL Load Test utility. Here is a link to some different ways to use these utilities to achieve your goal using profiler or other stock utilites. 

You can simply run profiler during a normal load that you would like to record, save it off, and replay it against the server to load test under realistic load. If you are using SQL server 2012, you can use the Distributed Replay utility for performing this same kind of testing, but from multiple sources to simulate load. If you are looking for a commercial option, you could look at Quest Software's tool called Benchmark Factory that can be used to perform SQL Server load testing.