The main thing to consider when building a long putter is the head weight. The lie angle is another consideration if you are going to need to make it more upright than usual. Long putters require a heavier head weight to maintain head feel because the longer shaft and grip (usually a heavier grip is used) have a counter balancing effect. Depending on how long you’re making it and what kind of grip, 370 grams of head weight would be the minimum to consider, in most cases. The Moment putters will work, but also the Pure Track putters are an option. All have head weights that are usable in a long putter set up. You will need to look at the lie angles to make sure they will work with what you’re trying to do. The 90 degree bore with a hosel adaptor providing a 79 deg. would be the way to go if you need that kind of lie angle. May not be able to get that upright with some of he Pure Track putters. You could with the MA0330 PTM5, but that would be the only one.