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You have listed a lot of components but you have not actually told us what you are planning to create. It's much easier to give useful advice when we know what the project is.
Based on what you have said I have no idea what the stepper motor is to be used for or what type of stepper motor might be suitable. If it is a bipolar stepper motor then a specialised stepper driver (such as an A4988) would be very much better than an L293. But without knowing the specific motor I can't say if an A4988 will be suitable.
A 1 amp power supply seems on the low side for three servos. 3 amps or 5 amps would be better.
How will the stepper motor and the water pump be powered?
Hi,
Welcome to the forum.
Please read http://forum.arduino.cc/index.php/topic,148850.0.html.
What is the reason for a keypad, rather than just a start button?
Thanks.. Tom.. 
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Querty:
The main idea of the project is a vending machine for liquids. It has a sliding rail and some small containers . The servo's will be placed on the containers and will open them when a specific keypad will be pressed .
A diagram would help to make all this clear.
The stepper motor I choosed for this project is a Nema 17 1.8A
[...]
As for the Stepper , I was thinking at a 9v 2A power supply maybe , as I do not need to run it at full torque .
.
An A4988 cannot provide 1.8 amps without overheating. A DRV8825 would be better
9v is on the low side - very near the lower limit for both the A4988 and the DRV8825. I suggest a 12v supply as the minimum. If the stepper motor needs to move fast then a higher voltage may be needed.
Make sure to adjust the current on the stepper driver to protect your motor.
It should be possible to power everything from a single 12v power supply (perhaps 5 amps) with suitable regulators to drop the voltage for the pump, the servos and for the Arduino.
...R
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Querty:
I did a lot of research about the maximum power that a breadboard can take and I am still not sure about this thing.
If you mean a solderless breadboard then I suggest you don't run motor power (including servo power) through it. The connections with a solderless breadboard are only intended for small currents.
Also the connections in a solderless breadboard would not be reliable for a long term project even for signal currents. They are only intended for prototype testing.
...R
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