I will need more information regarding the expectations you have from such a project. WAN optimization based on techniques such as compression can vary greatly in results, depending on the type of data being transferred. Granted there are some other WAN optimization techniques, but the most important factor is what/how much bandwidth optimization you are expecting to achieve.
Also, how mutable are the two servers, and what operating systems are they running, because some implementations may require the use of a modified (Linux) kernel to function properly.
Last but not least, the 300Mbps connection(s) that you have, what WAN technology is it based on? As this can have a considerable effect on the techniques that can/should be used to optimize traffic.