45 sheeps on the road :
Is the Cooler Master TX3 EVO good enough for an overclocked AMD A10-6800k?
Yeah it will be good for your APU.
Hyper 212 evo is usually used with overclocked cpu's which are more powerful like fx8series or i7 or i5
Hyper 212 evo will provide you 2-3°C lower temperatures than Tx3 evo but is also more costly and is very big.Until unless your cabinet can accomodate cpu fan upto height of 160mm you wont be able to use hyper212evo.
CONCLUSION-For your current APU Tx3 evo is more bang for buck.But if only your cabinet can accomodate Hyper212evo and you have the budget and you want to be futureproof(in case you change your APU with more powerful one) then go for Hper212evo