I currently have a set of three AV500 powerline extenders - one is connected to my router, one provides and RJ45 ink to my solar power inverter to provide monotoring info

and one is connected to my external office to provide an RJ45 link for my office computer. 

My fibre boadband provides around 50mbps at the router, but I'm only getting around 15mpbs at the office through the AV500 (incidently the upload speed seems to be about 20mbps at both router and in the office - making upload in the office faster than download).

I'm thinking of replacing the adaptors at the router and in the office with either a AV1000 or AV2000  pair to improve etworl speed in the office.

What speeds should I expect in the office with a AV1000 as compared with the AV2000?   

Would it be possible to keep the existing AV500 connected to my solar power inverter and re-pair it with the AV1000 or AV2000 without compromising the speed of the office connection?