I've never tried a corona mill, but I think the best first mill for any brewer would be the "Barley Crusher" maltmill. Its made for beer so it comes to you ready to go. Most other mills you can buy require you to add a base, hopper, and a handcrank (or drill). The Barley crusher comes with all these included, for less than $100. $80 last time I checked.
Brewmaster's Warehouse carries them.
Personally I wouldn't go with anything but a malt mill with rollers... your grain crush is very important, and can lead to alot of frustration or botched batches if done improperly.