Here’s one piece of advice I’d give to take advantage of your situation: whether you choose to include smart switches now or not, plan the wiring for them. Code now requires neutral at all boxes, so that’s one problem taken care of, but another issue is three-way lighting – there are may ways that can be wired for non-smart switches, but only some of those ways will work for smart switches. See the discussion here for an example.
I personally would probably put z-wave switches in at most if not all positions, even if I don’t plan to network them right away. It’s an established protocol, that most systems support, and I don’t think there will be any major changes that affect switches in the immediate future. But it’s an investment. If you don’t do it now, go for the cheapest switches you can, so you don’t feel bad replacing them when you upgrade.
edit to add: my understanding is that z-wave 3-way switch configs, with a master switch and accessory, will work even without the z-wave being setup. That is, the accessory tells the master what to do locally, not through the z-wave network.