Can you give some advise for my buck regular circuit?

I'm designing some hardware using EasyEDA. I'm planning to do the PCB and SMD assembly. I just got my first print last week, and i'm very happy with the price and quality. 
My current design features a Arduino mega on a PCB with a 3" OLED, some LED,s chips, and expansion ports. I need to power the circuit with 11~15V from a car battery, and am looking to use a more efficient regulator than the AMS1117 on the Arduino.
So i want to convert 11 to 16V to 5V, and i'm targeting a current usage between 200mA and 1A (the 1A is for future expansions)

The manufacturer SMT service has a very limited list of basic components, and i want to prevent extra charges from their extended library. I made quick evaluation of the available types below:

So i wanted to go with the last one. I played around with their great design tool, but i can really get the efficiency above 88%. This means i hit the maximum dissipation of the SOT-23-6 package before i get to 1A. This may be acceptable, but i rather go up to 1A and don't love the idea of the component working at its maximum dissipation.
I'm kind of getting the idea that it is not realistic getting getting more than 1A out of SOT-23 or SOIC-8 package buck converter. Is this true, or am i doing something wrong here?
Which regulator from the list would you pick?
This will also be the first time i work with coils. How does choosing a higher or lower uH effect the efficiency of a buck converter? I understand the advantage of a higher current coil, and a lower DC resistance.
But what is a smart SMD package size to choose? There are so many options here.
By the way, i'm also trying to keep the BOM costs low, as i may want to bring this product to market. That is why i did not choose the LM2576.
Also while on the subject; Is there a reason all Arduinos use linear regulators? Are there disadvantages to supplying the 5V pin with a buck regulator?