You have two choices:
Off the shelf Seed board module: SPI encoder -> your code to translate angle/velocity to TX/RX CAN frame -> Seed module 1 -> Twisted pair cable -> Seed module 2 -> your code to translate TX/RX CAN frame back to angle/velocity signal
My SPI board: SPI encoder -> your code to translate angle/velocity to SPI CAN frame -> SPI/CAN board 1 -> Twisted pair cable -> SPI/CAN board 2 -> your code to translate SPI CAN frame back to angle/velocity signal
The difference is that in case #1 you use TX/RX which is built into the core code of pretty much any MCU and the case#2 you need to use the thirs party SPI/CAN library.
Also you need an MCU with two SPI busses. I am using STM32 which has two busses, no problem, I dedicate one bus for the sensor and another for the SPI/CAN. The difference is that TX/RX is very slow, at most you can get to 115200 baud without any monkey business, however, SPI is up to 10MHz fo you will first saturate the CAN before you saturate the SPI bus, which is good. Generally the CANBUS could be utilized up to 30% signal saturation before you start getting error frames in the base case and up to 80% in modern implementations. That’s why it is generally preferable to leave the low lever handling to a middle man rather than solving this with a bare MCU and transceiver. If you notice, the Seed module has an atmel chip with code inside already handling all that nasty business and you are guaranteed clean frames. Same with the SPI MCP2515T-I/ST module. Actually the Seed goes a step further, I guess, because they already use MCP2515T-I/ST which is piped via SPI to the atmel chip and then you connect to the atmel via tx/rx. That Seed solution however may be too slow for your case since you control a motor, and I have no idea of the latency either, must be unusable for fast angular sensor. Currently I am working on a solution where I handle CAN directly via a transceiver and this is a real pain in the back because I need fast speed and no latency. However I think the MCP2515T-I/ST would be good enough. Watch out for the latency however.
Edit: You could also try Option 3, MCU directly to transceiver if it has built-in CANBUS but that’s like bringing a knife to a gun fight. I made it work on stm32f103 and my butt is still hurting.