AC – Yes, I am aware that we don’t go shopping for a psak or for a Rov who will give us such a psak, but it seems that he wants a yeshiva that will give him piskei halacha, which is not really the job of the yeshiva to do. If he doesn’t want his wife to wear a sheitel, then he should stipulate that when going out on shidduchim. If he doesn’t want his Rov to tell his wife that his own wife wears a sheitel, so it’s OK to wear one, then he should pick a Rov who holds like this for himself.
I had experience with this as far as my husband’s Rov’s wife does not wear a sheitel, but I was not prepared to go without for the rest of my life, but he told my husband (before we closed the shidduch) that his own mother and the Brisker wives (my husband and his Rov are Briskers) all wear sheitels, so it’s OK for me to wear one also. Simply the Rov’s mother-in-law did not wear a sheitel, so her daughter also does not. His daughters also do not, but it is OK for his talmidim’s wives to wear them.
This whole issue of sheitels has not one thing to do with learning in a Brisker yeshiva, as their limudim have to do with korbonos and kodshim, so no learning about sheitels in that yeshiva. This is an issue for a Rov or one’s personal feelings in the matter.
If the bochur wants to learn in Ohr Somaych or Aish HaTorah or any of the other BT yeshivas – BTW – I would not recommend a Belz yeshiva if he thinks a misnaged yeshiva would be more appropriate because they probably want people going there who have some connection to Belz chassidus and will be Belzer chassidim, not simply because of the sheitel issue. I also happen to know a lot of Belzer wives who do, in fact, wear sheitels.