Sway bars are great for handling as long as you know what they do. A front bar will, along with making the cornering "flatter," with less body lean, make the car understeer.
That is, in a corner, it will want to keep going straight more than it does now. The thicker the bar, the more it'll do this. Understeer is what all OEMs engineer into all road-going vehicles today. They want the car to "push" in turns even though that's not ideal "performance" handling.
Why do this?
Because the alternative is OVERSTEER.
If you put a sway bar on the back of your car (with none or a too-small one on the front), it will tend to oversteer.
That is, in a corner, it will want to turn even more than you do, and the back end will try to beat the front end through the turn. Obviously: not the best.
Manufacturers make cars understeer because it's safer for the kind of unskilled, ham-fisted idiots (i.e.: us) to which they sell cars. If you're in a turn and the car is understeering, your natural, instinctive reaction is to hit the brakes.
This usually solves the problem! GO SLOWER IN THE TURNS.
Whereas, if your car is oversteering in a turn, you also have a tendency to hit the brakes. And this tends to make you crash.
Now, if you want more "bite" in the turns, you want softer tires. Less air is the best initial thing. Softer rubber is going to make it even better. Wider, softer rubber is better yet.
On your car, I'd run a stock Beetle bar (13mm I think?) with maybe stiffer bushings than stock. That will make it corner a little flatter and give it a little understeer, which will inspire confidence.
If I went with the big aftermarket bar I'd use rubber bushings and add the rear bar as well, also rubber bushed, to keep the handling balanced.
What I would NOT do is run the large, aftermarket rear sway bar with a stock, small front one—unless I was trying to make a drift car.