The OP said "best and safest" so, because in 18650 the safest = 30A, I have to recommend the best performing 30A battery available to us right now, which is the Samsung 20S. Like I said at 90W with dual 30Qs or dual VTC6s in an affordable regulated mod, the vape performance typically starts to decline long before the voltage cut-off of the mod is attained, as the accuracy of the chip just cannot cope that well with the bigger voltage sag you'll get from these batteries if vaping on them at that wattage. So the mAh rating alone does not reflect the real world vaping time, as the voltage also plays a part, both in terms of how the chip inside the mod reacts to the voltage sag and in terms of the fact that getting less volts also means the regulated mod will increase the amp load in order to sustain the wattage required, thereby discharging the battery faster, i.e. obtaining less mAh from it compared to what you might have anticipated. It means the difference in actual vaping time often tends to be a whole lot smaller than most people would have you believe. Getting a few more pulls at the sacrifice of letting the batteries run warmer causing them to age faster, as well as at the sacrifice of running them at the recommended maximum safety limit instead of running them safer below this maximum limit, proves to be often not really all that smart after all. Way too many people wrongfully assume all regulated mods remain unaffected by the voltage sag of the batteries when it comes to the mod's vape performance. If using the 30Q or VTC6 at their recommended maximum safety limit, you can expect performance will suffer, often to the point where you will regret having bought these batteries after you compare them to 25A batteries. But I'll agree that going for the 30A Samsung 20S might be a bit overkill in terms of the safety, albeit that is for the OP to decide, as a 30A battery is still safer than a 25A one, and that is still regardless of how anyone wants to put it.
That said, the 30Q and VTC6 already are superseded by newer batteries, i.e. the VTC6A and the Samsung 24S. Similarly, the VTC5D also is better than the VTC5A, and, as we've previously discussed, also can be a wiser choice than the 30Q and VTC6 if you know how to correctly interpret Mooch's constant current discharge graphs (i.e. if you can remember who Alessandro Volta was).