Is messiahs name ינין or ינון? I know the vav and the yo'd are very similar, is this why it reads differently ?
This is a "Kri Ksiv" situation in which it is spelled with a vav and pronounced with a yud Note that it is a verb and it means will be magnified
יְהִי שְׁמוֹ | לְעוֹלָם לִפְנֵי שֶׁמֶשׁ יִנּוֹן (כתיב יִנֹּין) שְׁמוֹ וְיִתְבָּרְכוּ בוֹ כָּל גּוֹיִם יְאַשְּׁרֻהוּ
May his name be forever; before the sun, his name will be magnified, and [people] will bless themselves with him; all nations will praise him.
May his name: [May] Solomon’s name be remembered forever for his riches and his wisdom.
before the sun, his name will be magnified: All the days of the sun, his name will be magnified.
will be magnified: Heb. ינון, an expression of kingdom and dominion, as (Prov. 29:21): “he will ultimately be a ruler (מנון) ; (Gen. 21:23),” and to my son (ולניני) , “ who rules over my property after me; (below 74:8),” They said in their heart, their rulers (נינם) together" ; their kings together.
will bless themselves with him: A person will say to his son, “May you be wise and rich like Solomon.”
The idea of the name for the Messiah comes first from Tractate Sanhedrin which discusses Messiah's appearance. The context of the following comes from Psalm 72:17 -
b. Sanhedrin, Folio 98B
The School of R. Yannai said: His name is Yinnon, for it is written, His name shall endure for ever: e'er the sun was, his name is Yinnon.
Another mention of this same verse appears in Pesachim, Folio 54A, which discusses the pre-existence of the name of Messiah.
In other words, the word (or name) of ינון contains not only the meaning of (everlasting) perpetuity, but also of pre-existence.