Shooting LF may be challenging, it may be not for the budget minded, but as far as I'm concerned, it is the best medium for doing portraits, especially if you happen to have a good portrait lens. Platinum/palladium and their variants are an excellent choice because of the long tonal scale. You could also look into salt prints, which have lower resolution than platinum, and an even longer tonal scale. The downside is that you'll have to learn to make negatives for salt prints, which means even more overdevelopment than you would use for platinum, relative to development for silver gelatin printing.