Most rear sights require machining that will weaken the rather thin top strap of that small frame gun, plus the rear adjustable sight installations I can think of sit high enough that a new front sight blade is required.
I don't know if Taurus made an adjustable sight small frame or not, but all things considered it might be better to look around for one of the S&W Model 36 revolvers with adjustable sights and do a trade. I think it would cost less than the sight job, assuming someone would do it.
Jim