Could anyone help me translate this proverb from English to Irish?

My wish for you is: [...] That you may always have a friend who is worth that name. Whom you can trust, and who helps you in times of sadness. Who will defy the storms of daily life at your side [...] This is my wish for you, and all who care for you. This is my hope for you. Now and forever.

Go raibh math agat!

I'm not sure exactly what structure you are looking for (i.e., did you want the "my wish is" repeated each time?), nor whether so many clauses can run together intelligently in Irish, but here's a suggestion which essentially conveys the meaning. Be sure to wait for others to comment (and perhaps suggest better phrasing):

Tá súil agam go mbeidh cara agat i gcónaí is fiú go dtugtar cara air;
My wish is that you will always have a friend who is worth being called a friend;

duine is féidir leat do mhuinín a chur ann;
a person in whom you can place your trust;

duine a thabharfaidh cuidiú duit nuair atá brón ort;
a person who will help you when you are sad;

duine a sheasfaidh ar do thaobh in aghaidh stoirmeacha na saoil laethúil.
a person who will stand by your side against the storms of daily life.

Seo mo mhian duit, agus do na daoine go léir atá a gcroíthe istigh ionat.
This is my wish for you, and for all who care for you ["have their hearts in you" -- a very traditional way to say it].

Seo mo mhian duit, anois is go deo.
This is my hope for you, now and forever.

_________________
I'm not a native (or entirely fluent) speaker, so be sure to wait for confirmations/corrections, especially for tattoos.

A ChaomhinSF, is clásail choibneasta indíreacha cuid de na clásail choibneasta sin, agus tá 'saol' firinsceach.