In case that you already own 4460 (or have a good offer for it), yes, it will provide substantial boost in gaming over 8320. But if you don't, consider a newer chip instead, from at least 6th gen, preferably 7th. If for nothing else, then for DDR4 memory, which is here to stay with us for a while. Haswell CPUs still use DDR3, and once you decide to upgrade, you will have to buy new RAM as well.
Also, there is simply no reason to get Z97 board. Get H97 instead. I own the same CPU (4460) with a Z97 board, and was thinking the same way back then (future upgrade or overclocking). Guess what came out of it. Nothing. You will likely change the entire platform instead of swapping the CPU to unlocked CPU from 4 series.
Ive not actually bought it yet, For my budget of about £130 on a CPU it should be suffice. Currently my 8320 at 4.0ghz combined with an overclocked 970 runs any game apart from a small handful like arma where i need more cpu power for faster frame rates.
hopefully in the next few weeks il get it all set up. il have a look at the H97 boards whats the reasons for buying that instead of the Z97