UTR sequences after IRES - (Dec/05/2012 )

I'm trying to construct a lentiviral expression vector containing
EGFP - IRES - gene of interest.

Since there are important regulatory elements for my gene of interest in the 5' and 3' UTRs, I'd like to use the full cDNA clone instead of just the sequence containing the open reading frame.

Would there be any issues with this?

You should at least identify and omit the polyA signal from your transcript (in eukyarotes usually AATAAA sequence), which would cause polymerase to end transcribing before new cistron for EGFP starts. Not sure is something else is needed.