Yes you need Ultimate. It's what I have and it's through Ultimate that you get all the Test add-ons. To do effective Load Testing it also helps to have the Test Controllers in place as well so you can direct the tests from another machine.
I run the tests from my work laptop on the virutal lab, and direct the results to a database for archiving. The local files you can get for the Load Tests can get quite large, and unless you have a large disk space you need to cull the older results after awhile. At least with the database I can pull out older results and graph them to see how the system is doing long term.
Nothing learns better than experience.
"So as I struggle with this issue I am confronted with the reality that noting is perfect."