Please also have a look at the book Nagarjuna in China: A Translation of the Middle Treatise, which is a translation of Nagarjuna's Madhyamaka Sastra with the oldest known commentary by Pingala or Vimalaksa (c. 4th century), translated by Brian Bocking.
This text is from the Chinese Zhong lun. Due to modern Buddhist studies heavy source bias towards Sanskrit and Tibetan materials, this version which includes the oldest commentary--quite a bit older than Candrakirti or others--is often overlooked.
In a similar vein, the Mahaprajnaparamita Upadesa (Dazhidu lun) is also very important. This is a commentary on the medium sized Prajnaparamita sutra, all ultimately given from the Madhyamaka point of view. Again, due to source bias in modern scholarship, it is often overlooked. There is some debate on the authorship--was it really Nagarjuna or not? But, even if it wasn't, it's still one of the earliest Madhyamaka commentaries that we have, particularly for Prajnaparamita material.
These two texts are critical for East Asian understandings of Madhyamaka / Nagarjuna,etc.