Up to you what you do but,
YES same bearing core on T3/(34/35)/T4.
Assuming you have your old turbo, I would send that for a rebuild and get your money back.
You need to spec the turbo to the engine, but T34 will work with a std engine or modded one, but depending on what has been done ? a different one may be more suited.
I use Craig/Andy at the TURBOCENTRE 01924 404112, good honest lads, do all the mods as well.
tabetha