Unfortunately it's hard to find a dev kit board that can meet all your requirement.
You can checkout all available dev kit board from below link
The best I can do is to comment on roughly where you can find certain dev kit board that can meet certain criteria as specified by you.
- High Speed USB2.0(with 40Mbps Speed)
- USB 2.0 feature support can be found in typically dev kit board with SOC FPGA like Arria 10 SX or Stratix 10 SX dev kit board
- DDR3 SDRAM
- DDR3 SDRAM is used mainly on older FPGA dev kit board like Stratix V, Arria V and Cyclone V
- For newer generation FPGA product family like Arria 10, Stratix 10 and Agilex, we have move on to use DDR4 instead
- I/O Logics Will be >700
- Ideally you are looking for Arria 10, Stratix 10 and Agilex type of newer FPGA device that comes with larger IO capacity but do take note that even if the FPGA contains all the IO count number but it may not be necessary bonded out in dev kit board