Bob,
You asked about the Zen series. I flew a Tai-Ji .60 for a season and would stand behind that airplane as a solid F3A platform for starting out. Less expensive than the Piedmont models, it also has one advantage for a flyer not overly familiar with F3A set-ups and that is simply that it is very easy to set up well with conventional equipment. It flies honestly and is very smooth. It is not a wide bodied design but by no means is it small either. While fine with the YS91, the YS110 would be the ultimate choice. It is large enough to present well in the air and flies well enough that good thumbs can pilot it into a high finishing place in any but the more advanced classes. I understand the Zen series improved upon it but cannot personally vouch for it. It is worth your consideration.

To narrow your choices, take your budget, check out the various choices while adding in motor, pipe, header costs, and the best servos you can afford (I would try to go Futaba or JR for no question accuracy on servos) before you take an airplane that leaves your budget short on other quality accesories that make a real difference in the air.

Mark