Figuring Out Pin-Header Size for Socket from Datasheet + Ordering Specific Pin-Header Size
Answer to Question 1 - From the manufacturer's data sheet for that part, you need circular pins 0.015-0.025 in. or rectangular pins 0.010 * 0.018 in. (See picture below from data sheet)



Answer to Question 2 - Use the parametric search on your favorite vendor's web site.