BSD and LWSD are very strict about accepting different testing. To be honest, I don't think they will accept WISC-R at all. They reject any testing even if it is different form of COGAT. ITBS is not related to IQ, it is an academicals testing includes both reading and math.
Getting a private tutor for English along with regular BSD/LWSD might be an option. Even though I don't have any experience with ELL, I feel it won't be enough for him. These district's yearly testing is in Jan/Feb.
There is one more private school you might want to check. Bellevue Children's Academy (
https://bcacademy.com/#) This school is academically rigorous and it might be good option to prepare him for the gifted testing (if they accept ELL students).
