if i understood you correctly your wanting to know what brand of ram or what speed. the speed depends on the options you wanted. standard offered atleast for me was 1333MHz. and the ram is made by hyundai. download cpu-z and it will tell you all the info you wanna know
32 gigs of 1600 is ok. i dont own an r4 so im not 100 % sure about quad channel. but i could have used triple in the stock motherboard. im running corsair vengeance. any brand will work. as long as the timings are the same.
That's a lot of memory I haven't seen anyone order it from dell always after market to keep price down. As long as the speed and timing are the same should work. If your mostly gaming 16gb is more than enough. Thats a lot of money unless you need it for work.