APUs are not gaming systems, they are made for low cost, low power, low demand 'average users' for Email, Websurfing, etc. The APUs do not even meet the minimum requirements
http://www.geforce.com/games-applications/pc-games/grand-theft-auto-v/system-requirements .
That said, considering how low end the APUs are, even if you did get a 750TI (which is a very low end GPU) you would have to pair it to a i7 EE in order to get 30FPS as this benchmark shows http://forums.anandtech.com/showthread.php?t=2428094. As a APU is very very very much not even near a i7EE performance level, you wouldn't be able to or be in single digit FPS level with that hardware.
PC Gaming is expensive if you can't afford to replace your system (you need to replace CPU, the GPU, and that means PSU as well) then stick with a PS4, for only $200-400 you can play GTAV 1080P High @30FPS and many other titles at 60FPS plus you get free BluRayPlayer (3D!!), FREE Wireless Controller, FREE Gamer's Headset that is $200 alone you have to add on to any upgrade costs you would be considering when replacing your PC as well.
Care to check for yourself? Simply go to www.canIrunit.com and select the game and it will tell you how your computer stacks up.
REMEMBER: MINIMUM Means playing 1024x768 Low graphics and getting AT LEAST 15FPS
RECOMMENDED: Is the true 'gamer's experiance' as 'I saw on youtube'.