Well, I can't contribute much to your question. But would surely like to point to some verses in Bible which says of the saints.

Psa 145:10 All your works shall give thanks to you, O LORD, and all your saints shall bless you!

Dan 8:24 His power shall be great--but not by his own power; and he shall cause fearful destruction and shall succeed in what he does, and destroy mighty men and the people who are the saints.

Mat 27:52 The tombs also were opened. And many bodies of the saints who had fallen asleep were raised,

Act 9:13 But Ananias answered, "Lord, I have heard from many about this man, how much evil he has done to your saints at Jerusalem.

Act 9:32 Now as Peter went here and there among them all, he came down also to the saints who lived at Lydda.

Act 9:41 And he gave her his hand and raised her up. Then calling the saints and widows, he presented her alive.

Act 26:10 And I did so in Jerusalem. I not only locked up many of the saints in prison after receiving authority from the chief priests, but when they were put to death I cast my vote against them.

Rom 1:7 To all those in Rome who are loved by God and called to be saints: Grace to you and peace from God our Father and the Lord Jesus Christ.

Php 4:21 Greet every saint in Christ Jesus. The brothers who are with me greet you.

Php 4:22 All the saints greet you, especially those of Caesar's household.

Rom 16:15 Greet Philologus, Julia, Nereus and his sister, and Olympas, and all the saints who are with them.

1Co 1:2 To the church of God that is in Corinth, to those sanctified in Christ Jesus, called to be saints together with all those who in every place call upon the name of our Lord Jesus Christ, both their Lord and ours:

1Co 14:33 For God is not a God of confusion but of peace. As in all the churches of the saints,

Eph 3:8 To me, though I am the very least of all the saints, this grace was given, to preach to the Gentiles the unsearchable riches of Christ,

2Th 1:10 when he comes on that day to be glorified in his saints, and to be marveled at among all who have believed, because our testimony to you was believed.

All these verses are from ESV version.

If it is enough for you to know who are the saints then it is a pleasure for me. Or in case if you want more reference to this word SAINTS do let me know. I'll be glad to help you to find it in whichever version you want.

From my part, I think SAINTS refers to the people who are in Christ or say believers of Christ completely dedicated to Him. So of course it is a blessing for them to be at His Marriage Supper. But if all the good people are saints and the wedding gown in said as the righteous deeds of the saints. Then afterall who is wearing that. Who is the bride here?