For test patterns I'm using a handheld box I got from tequipment.net, you can find an old thread discussing it here:
http://forums.arcade-museum.com/showthread.php?t=99024
Another way is a jamma harness an Atari Tetris board, only because its small and makes nice test patterns.
And as for the rejuv, definitely the B&K mentioned above is what most people use. Note that that there is a big difference between the 470 and the 460, so anything 470 or newer depending on how much you want to spend.