For a beginner, I think that the tail servo selection is less critical than the gyro selection. Get a GY401 or better.
Now, if you are going to purchase a GY401, look at the prices of the combos that come with a digital tail servo. You might decide that it is worth it to get that as well.
On a scale from bad to good, 1 to 10, I would rate things like this.
1-Average gyro with average analog servo
2-Average gyro with top digital servo
9-GY401 with average analog servo
10-GY401 with top digital servo

Of course, once you move to more advanced flying, fast backwards flight and 3D, then the performance of the tail servo becomes much more important. But for a beginner, the gyro is the critical piece of hardware.

Vince