Before deciding if and what to swap to I suggest you think about and set your objective. What is it you are trying to accomplish?
I assume you want to make the switch because you prefer the look of newer items rather than trying to change the handling characteristics of the KZ650 in any meaningful way since the stock items can be tuned to perform at a level above and beyond the level of performance provided by even a highly tuned KZ650 engine. An exception might be if the bike is to be used primarily for drag strip runs in which case a longer swing arm might be beneficial.
Is there a particular look you are trying to achieve? Ed
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
