Wich one is better?

I'm not a Glock fan and I've never heard any longevity ratings on the Walther but I rarely see used P99's for sale...

I have to say the Walther is a much better shooter.

So is the Walther a bad buy?

P.S.(And i ask a Glock 19 because there both 9's)

Personally I'm a Glock fan so I'll say go with the Glock 17.  Darn fine pistol, and Hi-caps are available.  However I do prefer the G19 to the 17.  The 19 can use G17 magazines, has a long enough barrel for service use, but is compact enough for CCW.

I don't know if you could necessarily call the P99 better than a Glock 19, simply because the P99 is still a bit unproven.  In my opinion, the Glock has several major advantages over the P99.
1. Tons of aftermarket parts are available
2. Hi-Cap mags a readily available (expensive)
3. Glock armorers can be found at any Gun Show, and will willingly help you with any Glock-related problem
4. Proven reliability

However, with that being said, I would still pick the P99.  Ergonomics are WAY better with the P99, which enables the gun to "point" faster.  I like the ambi mag release feature, and the trigger is also better than the Glock's.

I have shot both and I am not a big fan of the Glock to start with, the Walther is expensive and the High cap magazines are hard to find but in my view the Walther 99is a superior gun. The different grips give you a wide range feel for the gun; different hand sizes will fit better. I would go with the 99

I have owned both...and prefer the P99.  Not that I'm saying anything negative about glock but I find the P99 to be much more accurate and easier to shoot well...
The only drawback to a P99 is the availability of hi caps.  But to me a hi cap is not a big deal...being able to shoot the gun well is most important