Jump on the pledge store, you can still get CCU's. I just checked and saw both CCU's from Heartseeker and Hurricane (Non warbond). Only other option is something from a Nomad. I use 315P to Nomad Warbond for something like $5 then use that as a base to LTI CCU.
You could get the Warbond CCU 315P to Nomad, then either upgrade a 315 you have, or melt a ship and use the credit for the 315P and the rest for the Corsair (won't cover all of it).