I can't speak for anything IMM puts out, because I don't own a set...BUT, reports of owners on here who have purchased his wares would encourage me to say, simply:
Yes...I would use IMM heads with any SB build. Only caveat would be simply, if I were looking to do something specific (like your citation of a 250@050 cam), I'd contact Brian directly and ask for guidance as to what spring rate I'd need, or what retainers he'd recommend...which is a good idea anyway if you're going to sink that kind of money, and you have the opportunity to speak with the builder.
