The key to doing any type of research on WW2 vets through govt. sources is their service number.It's virtually inpossible to get any info without it.
Regarding your great uncles, nothing beats oral history.If they're still with us, write to them, call them, tape record them.See if they still have copies of their discharge papers.Depending on how deep you want to get into their history, this might be all you need.
There are many unit association/reunion websites on the web, but they're only as good as the info put in them. I've seen a couple with complete rosters, but most contain general unit histories, announcements of upcoming reunions, etc. Try a google search for your great-uncles (and be thankful their names weren't John and Joe Smith!!).You might get lucky.
Regarding Bernard McGoldrick:yes, T4 is is rank.It stands for Technician 4th grade, basically a sergeant with a technical speciality.
My sources show Bernard Goldrick, SN 31196056, initially buried Grand Failly Cemetery, Longuyon, France.Remains later repatriated to a private cemetery in Connecticut.