Omitting words
Hi, there
I have a question about omission in English. Do these sentences sound strange?
A. (in a store): I’ll take three HDs. One 250gb and two 500gb
B. (in a store): Can I get three Iphones. I'll do one black 64gb and two silver 128gb
C. I have four guitars. Two steel string(s) and two nylon string(s)
My question is: Do these sentences sound odd? Can I omit the nouns at the end of them? In sentence A, can I omit “HDs” (two 500gb HDs”? In sentence B, can I omit “Iphone”? One black and two silver 128gb (Iphones). And in sentence C, can I omit “guitars”? Two steel string(s) and two nylon string(s) (guitars)?
Thannk you