You can find a YouTube playlist here with many of the songs suggested below.
Gathering
The final Sunday of the Christian year celebrates the Reign of Christ (or Christ the King Sunday) and there are many gathering songs you could use which pick up this theme. There are some great songs inspired by the psalms such as O worship the King all glorious above (CH 127), The Lord is King lift up your voice (CH 129 / MP 656) and Clap your hands, all you nations (PFAS 47D / GSW 15), a joyous setting of Psalm 47 from West Africa which would be very easy to pick up. You could also consider classic hymns such as Rejoice! the Lord is King (CH 449 / MP 575) and Jesus shall reign where’er the sun (CH 470 / MP 379) or Come people of the risen King (MP 1267 / CCLI / Getty) for a contemporary hymn. Some possible worship songs could be My Jesus, my Saviour / Shout to the Lord (CH 531 / MP 1003 / CCLI), High praise (CCLI) or Come and worship Christ the King (Resound).
Word
Instead of a Psalm, the second reading is a Canticle, the Song of Zechariah which is otherwise known as the Benedictus (not to be confused with the Bendictus qui venit). There are various metrical options set to well known tunes including Blessed be the God of Israel (Hymnary / PFAS 1032) and Now bless the God of Israel (Hymnary / link) which are both often sung to Forest Green and Bless the Lord, the God of Israel (Hymnary / link) which could be sung to Blaenwern or Lux Tremenda. O bless the God of Israel (Jubilate) is another metrical setting but with an original tune while Benedictus (OCP) would be an option for bands while its simple chorus could be used to sing this responsorially, as could the short chant Benedictus Dominus Deus (Taizé).
Response
Many songs which link to the Gospel are often associated with Holy Week but also touch on Christ as King, including Meekness and majesty (CH 356 / MP 465), Heaven shall not wait (CH 362), The head that once was crowned with thorns (CH 438 / MP 647), All hail King Jesus (CCLI) and King of kings (CCLI). Jesus, remember me (CH 775 / Taizé) would pick up on the words of the criminal in v42.
There are some great songs which are based on the Colossians passage, including Christ, of God unseen the image (CH 453) - which is essentially a paraphrase of vv.15-20 - Christ, you are the fulness (Hymnary) - which adds on paraphases of verses from chapter 3 as well - and The Colossian hymn (Gordon). You can also use other songs which pick up some of the themes from the passage such as How shall I sing that majesty (CH 128), Across the lands (MP 1141 / CCLI / Townend) and Come and worship Christ the King (Resound).
The Old Testament could link to songs about Jesus as a shepherd, including settings of Psalm 23 such as The Lord’s my shepherd, I’ll not want (CH 14 / CH 15 / CH 16), The Lord’s my shepherd (MP 1008 / PFAS 23F / CCLI / Townend) or The King of love my shepherd is (CH 462) while Your hand, O God, has guided (CH 511 / MP 705) speaks about God’s flock. Hail to the Lord’s anointed (CH 474 / MP 204) would make an explicit link between David and Christ as well as giving a nod towards Advent. As well as the German chorale melody there is a version of the latter for band set to a traditional Irish melody by New Scottish Hymns (New Scottish) and a new version by Indelible Grace (link). The short chant The kingdom of God is justice and peace (Taizé) could link well to v5 and could be useful for a sung response to prayers.
Sending
You could finish by singing praise to Christ the King with hymns such as Crown him with many crowns (CH 459 / MP 109), Christ triumphant, ever reigning (CH 436 / MP 77) and How shall I sing that majesty (CH 128). Alternatively, you could focus more on our calling with worship songs such as Hear the call of the kingdom (MP 1282 / CCLI / Getty), Build your kingdom here (CCLI) and Let your kingdom come (CCLI) or short songs such as Sent by the Lord am I (CH 250) and Sizohamba naye / We will walk with God (CH 803).