Power mirrors for 2015Yaris L

[YarisCA]

I am new to this forum and now own a 2015 Yaris L(1st car).
So I am looking to add extensions like power mirrors to start with.

I went through http://www.toyodiy.com/parts/g_U_201501_TOYOTA_YARIS_NCP131L-CHPRKA_4.html

Looks like I need
87910-0D550 OUTSIDE REAR VIEW MIRROR-ELECTRIC REMOTO CONTROL DOOR MIRROR 1
87940-0D550 OUTSIDE REAR VIEW MIRROR-ELECTRIC REMOTO CONTROL DOOR MIRROR 1
84870-0F010 OUTSIDE REAR VIEW MIRROR-ELECTRIC REMOTO CONTROL DOOR MIRROR 1 $154.95

Now my questions are more of validation before I buy.
1. Would these parts come with necessary cables?
2. Is there anything more I would need?
3. I couldnt find the DIY guide for change to power mirrors for 2015 Yaris L. Can someone help me find it?
4. I am planning to buy them from https://www.oempartsource.com, is there a cheaper place to find them?