I think those shafts should work out very well for your setup. I also think 150 grain points/broadheads are a good choice. The problem is, given that you already have the shafts and want to use 150 grain points, that only leaves length to fool around with. The second problem is, how are you going to know when you have the right length? Are you going to bare shaft tune? Usually when you bare shaft tune based on length, you start full length and cut off a half inch at a time. If you want to bypass all of this, just have them cut the shafts to 29” and don't worry about it until you get into bare shaft tuning. 29” can't be that far off.