Is this sentence flawless? (Over there is a Japanese airplane or There is a Japanese airplane over there) Couldn't type the kanji on the keyboard.
'Asoko ha' would describe the location 'there', i.e., That place is a Japanese plane. This structure also doesn't work with the arimasu ending. 'Asoko ni' (in that location) would be correct.
'Nihon no' is too general. You need to say 'Japanese-built' (nihon-sei).
'Hikoki' is missing a sound, namely う (ひこうき）.
Either way would be fine. There is a slight difference in nuance: 'The Japanese-made plane is over there' vs. 'There is a Japanese-made plane over there'.
There is definitely a difference between arimasu and desu endings. 'There is' vs. 'It is'. ライオンです。It is a lion. ライオンがあります。There is a lion. Either way, you'd better run.