If I rip all my CD's to flac files do I still need a CD transport?

All my CDs are in FLAC on a server. The PC drive is sufficient for ripping with 100% integrity.  ( something no transport is capable of as it does not re-read, buffer and use error correction or compare to well known checksums.)   So, not for quality. Now, if you have CDs lying around, friends bring them over etc, then a transport can be handy.   Use case, not quality. 

tvrgeek

The PC drive is sufficient for ripping with 100% integrity.  ( something no transport is capable of as it does not re-read, buffer and use error correction or compare to well known checksums.)

You are mistaken. The compact disc standard includes two levels of error correction using Reed-Solomon code. Some transports (such as PSAudio) have extensive buffering and re-read capabilities.

Would I be better investing is a quality streamer and DAC?

I say yes; however, YMMV. I ripped my high quality CDs into my server/streamer and have never looked back at a CD player again, considering I had owned fairly alright CD players like McIntosh MCD 1100, Audio Research CD9, and Meitner MA-2. No regret.