Yosys is nice, but you aren't going to get around using vendors tools for configuring IP unfortunately. Vendors stopped supporting 3rd party tools a few years ago primarly because it was so hard to integrate the IP configuration. For instance, the last time I used Synopsys' tool (Synplyfy) I had to always have ISE or Vivado open in another window to configure IP.

Of course, for many things, you might not need to configure vendor IP. Examples where you most definitely need to are 1) Filters, 2) FFTs, 3) DDR controllers 4) High speed transceivers. In some cases you can configure vendor IP with language templates.

If you don't need these components, then Yosys will be good for you.