Yes, T'Prynn fought as her own champion in kallee-fee. The Vucan's Forge/Heart/Soul novels do detail Spock's marriage to Saavik. I don't know how old Selar's brother was, but there is dialogue about how he doesn't go thru Pon Farr, it's obviously intended that he will never go thru it, and implied that that is standard for gay male Vulcans iirc. Spock was speaking about his own situation though. I think it's a pretty broad interpretation to interpret that a gay Vulcan would be motivated to form a heterosexual union. T'Prynn certainly didn't seem interested in her male betrothed. I think what Spock means is that Pon Farr physically drives him to have sex, and by Vulcan tradition that means marrying first. Selar does "mate" during her Pon Farr in New Frontier, but she's explicitly not interested in marriage. It's worth pointing out though that she is a widow whose husband had died during Pon Farr a few years ago while mating with her - the excitement was too much for him apparently.