So do you have a motherboard? If so just use what you have and it should be fine. I assume you are using the i5 now, so just toss the GPU on that card and save the money.
What are your current and future plans because your cpu will bottleneck the GPU? If you aren't going to upgrade your cpu for roughly 2 years I would consider buying a GPU more appropriate to your cpu.maybe something like a gtx1050/ti or rx460, both are great cards and would cost much less.