According to cpubenchmark.net, which puts together a series of benchmarks to one overall score, they have the following scores:
i5-4460: 6,740
i5-4690K: 7,767
i5-4690K OC: ~9000 (only a guideline as it differs what you'll get which each CPU)
I would go for the i5-4690K, though getting a Z97 motherboard is going to cost you more, You'll be able to get the MSI Z97 G41 PC MATE at a good price.
Even if you don't get a Z97 mobo, the 4690K is going to be your best choice.
All of this is though based on that the i5-4690K is in good working condition, make the seller do a test run if it's a he/she seller and remember to get the receipt (if it does have a guarantee).
Hope this helped!