I would choose option 2, and in a way I have by buying a custom boat that lacks some systems finishing by way of plumbing, heating/ventilation and electrical.
1) Everything works quite well at the moment, but when I upgrade the electronics, they will be current rather than original 20 year old sounder and 8 year old plotter.
2) Some things, even if old, are fine and worth keeping, like the Force 10 stove and the Lavac head.
3) Some things are fine, like the SS tanks, but I am choosing to reposition them and change them to HDPE plastic to lower CG and reduce cross-contamination issues. While this necessitates a complete replumbing of the input side, it's my choice to do so. Same thing with an engine rebuild, new mounts, couplings, PSS, feathering prop: I want to reset the odometer on some systems to "zero" before we push off.
4) New stuff includes AGMs in a custom built cabinet, an inverter, solar, wind and a genset. More pumps, and a shower sump. An autopilot, a windvane, an SSB, an AIS, a radar, an EPIRB, a liferaft, a Portabote, a nesting dinghy. They just weren't there before. The electrical system is top-notch in terms of access and design, but needs tailoring.
5) Dorades, vents for tanks and exhaust going up through the pilothouse, positive air flow and exhaust for the engine bay, chimney for a diesel heater...this means some torch work (it's a metal boat) and an opportunity for us to learn basic welding, as does cutting a hatch into the saloon bulkhead to get into the forepeak "workshop" without needing to go on deck and lift a 20 kilo steel hatch.
6) Turning a port-side aft-cabin double into an athwartships double means that we simply switch pillows to the high side for sleeping underway. It also frees up several square feet for a small office/comm. station in a dry and relatively quiet part of the boat.
7) Bimini: There isn't one, and we need one to support a large array of solar panels.
All this costs money, of course, and time...lots of it. But I get to plan, for better or worse, for myself all these changes, and in planning, I get to learn how to do it right and how to fix issues when I find them.
Buying a "ready to go" boat means you're buying the ideas and quality levels of others, which is a crapshoot, and I have NEVER seen a boat I thought was "just add provisions, fuel and water and let's go!". Not once. They may exist, but usually an older boat has a range of older equipment, some of which may or may not make sense. Take a relatively static item in terms of technology like winches: I would not take offshore a boat with working winches for which parts no longer exist, like Barlow (an otherwise fine winch maker) or some others. Just an example, but it's the sort of decisions you frequently make in contemplating this sort of adventure.