I don't know where you are on your build, as I'm late to this thread. Even with a SSD drive, you can benefit from caching your disk accesses. I have PrimoCache, and it allows both Level 1 (L1, memory cache) and Level 2 (L2, fast non-volatile cache).
I have a 2TB SSD main drive, and a 1TB NVMem L2 cache drive, plus about 40 GB L1 cache (of 64 GB total RAM). When you get a page fault, PrimoCache checks L1, which loads faster than NVMem and SSD. If it's not in L1, it checks L2, which is faster than SSD. I sized L2 to be as large as possible so PrimoCache isn't flushing L2 contents any more often than necessary.
I found that after a while I'm mostly running out of L2 cache, which is at least 10 times faster than SSD. I have MegaScenery Earth Northern and Southern CA installed, and after the initial scenery load, reloading scenery is a lot faster, as an example.
I have a EVGA X299 FTW motherboard, with a couple of built-in NVMem slots. I bought a heat sink for the NVMem, to avoid heat throttling. I have a full-service warranty at Best Buy, so they did the build for me. I wasn't happy with their Windows installation, so I ended up reformatting the C: drive and rebuilding the system from scratch. All the annoyances went away after I did that.
I'm not a fan of XPlane, but use what you want. Just make sure the simulator of choice supports the flight model(s) you want to use.
You can have multiple simulators on your computer, and use which ever one you think is best.
FSX:SE no longer remembers settings from one session to the next so I'm using Prepar3D now. V4 is better than V3, and V3's graphics blow FSX:SE's out of the water. V3 is their last 32 bit simulator, and V4 is their first 64 bit simulator. If the Evektor SportStar Max model would load on V4, I'd use that in a heart beat, but V3 is perfectly acceptable. Last I checked, the most recent version was V5, but V6 might be out by now. I have no experience with V5 or more recent.