If you want friendly, I suggest that you get a single parakeet. A single will be much more likely to bond to his human while 2 or more birds bond to each other.(IMO, males are friendlier) Get the bird while he is young. If the bird has the typical striped patterning on his head, you can judge age by how far down towards his cere (fleshy place where the nares are) the stripes go. The less stripes, the older the bird. One concern is your cage. It may be designed for larger birds, in that case the bar spacing may not be appropriate for a parakeet. BTW, my understanding is that these birds are native to Australia, and the name Budgeriar means tasty meal, or some such!
https://en.wikipedia.org/wiki/Budgerigar
https://en.wikipedia.org/wiki/Budgerigar