Rashi: Orcha is Melech ha'Mashi'ach, who is compared to light - "Arachti Ner li'Mshichai" (132:17). Amitecha is Eliyahu ha'Navi, who is Amiti - Navi Ne'eman.

Radak: Orcha is salvation, the opposite of Koder (42:10). Amitecha is to fulfill Your word to gather us from all the nations.

Malbim: They are two matters that will bring the redemption. (a) Revelation of Hashem's light - "Kumi Ori Ki Va Orech" (Yeshayah 60:1). (b) The promise that Hashem made via His Nevi'im - He will make His promise true. These will lead from Galus and bring me to "Har Kodshecha."

Rashi: It is like v'Yevi'uni. Also elsewhere, the prefix [Vov] is omitted [before the second verb], e.g. "Er'eh Tzoncha Eshmor" (Bereishis 30:31).

Radak: It is Beis ha'Mikdash, which is [on] Har ha'Moriyah.

Malbim: It is Tziyon; Mishkenosecha is building the Beis ha'Mikdash.