If you need anymore information on other regiments; Ive attached the queue of the disbanded regiments, (187th in 5th place by Xao) which means that they are 5th place until regiments disband and create new places for the disbanded regiments
I believe all regiments on CW are booked in so becoming a CO is in high demand with little supply. If you wish to see more info, just message RHC from clone wars or you can check the Commanders Sheet
As Dank mentioned, 187th already has an interested party at this time, and is on the active queue to be reintroduced to the server.
Currently Xao is set to be the next Captain and CO of 187th, however if you wish to be involved in this coming generation of 187th, i'd suggest you get into contact with him.
The current rank structure only allows the donating commander to take the rank of Captain upon the regiment's addition, and unfortunately we dont allow for users to retain a high rank such as Captain after such a length of inactivity, and the disbandment of a previous regiment. If you were to join Xao's coming 187th, you would need to start from the bottom like everyone else.