Asking for useable graphics card on budget


in a few days I'll start building an "new" DIY-PC from existing parts. Video out will be a decklink 4k pro, mainboard, a fatal1ty Z87 Killer.

Because I have a low/no Budget for further parts, I want to ask for a cheep graphics card. I have do decide betweeen a Quadro K600 (I may be took from another PC) and something else better for nearly the same price (less than € 200,-). The PC will only/mostly be used for CasparCG - so no games, Office, and so on ...

My technical video plattform is on 1080i50 signals and CasparCG generats flah-based lower thirds and scorebugs for sports - animated template-versions will come soon.... Maybe playing some short clips for advertising and as stinger clips or in-/outtros.

Does someone have any ideas ?