Autonomous Arduino RC Car

Hello all! As a project I will (try at least) build an autonomous arduino rc car as the title suggests. For that I will be using the following: -Arduino Yun -an RC car http://www.maplin.co.uk/116-vw-classic-campervan-rc-662082

-Ultrasonic sensor http://www.amazon.co.uk/gp/product/B00C92X360/ref=ox_sc_act_title_2?ie=UTF8&psc=1&smid=A3MG0N098C51P8

-180* servo http://www.amazon.co.uk/gp/product/B00EJCCM9M/ref=gno_cart_title_3?ie=UTF8&psc=1&smid=A2A5KR87KHQ834

I choose the Yun because of the wifi. I aim to connect the "vehicle" with a computer via wifi to transmit data.

My first problem is the voltage operation. I posted a question on Motors,Mechanics and Power http://forum.arduino.cc//index.php?topic=194967.0 head over if you can contribute or here. In sort , will the servo (3.5-5v) + the sensor 5v be able to be powered from the arduino with a 5v input?

And secondly I will be connecting the arduino to the pcb of the rc car with wires. What ohm resistors should be used?

Feel free to discuss any problems that might arise and you think I might have not considered.

Thank you!

An Arduino cannot provide enough current to power a typical servo under load and you will need to provide your servo with an independent power supply. This might consist of a direct connection to whatever is powering the Arduino, if it is able to supply about an amp without making the Arduino's supply drop out.

As to connections between the Arduino and your "PCB" it is impossible to advise how to connect them without know the electrical characteristics of the "PCB" and what the connection is intended to do.

So the servo and the sensor will need a different power supply. Considering the sensor needs 5v as operating and the servo from 3.5 to 8v how many vs should the battery be? is it a problem if they are both on the same circuit but with different resistors.

If i get a hold of the datasheets what information would show or help calculate how many ohms the resistor should be?

Thanks!