For a new owner, I would want things to be easy and fast. This means you probably don't want to calculate ratios but rather just feed a wide variety and you probably don't want to buy a ton of ingredients.
Least ingredients but pricey [variety as always!]:
AWD
Moderate amount of ingredients but more complicated ratios [f/v with lots of Calcium]:
Original HPW
Moderate amount of ingredients with less complicating ratios [provide a wide variety of f/v & you are good]:
Orange Wombaroo
More ingredients with less complicating ratios [provide a wide variety of f/v & you are good]:
LGRS Suggie Soup
More ingredients with strict veggie/fruit list [fed f/v with high phos]:
BML
There are other diets that not everyone recommends or would suggest for various reasons; not popular, some reports of health issues, not fresh

, complicated, etc.
I use Suggie Soup and if you don't have a wild bird feed store or a trader joe near you then I also sell the powdered ingredients for easy access:
Suggie Soup Sample
When I get the Wombaroo supplement I use:
http://www.thepamperedglider.com/supplements.htm
This place sells HPW Samples if you want to try that diet out and if you are clever the HPW Samples can be used as AWD samples too.