I’d be one that says 200 watts is not enough . The OP did say that the 100 watt V4 didn’t have enough clean headroom... a 200 watt class D would likely have a little more clean headroom but not much. Remember, doubling the watts with all else being equal (which it never is) only gives you 3 dB more volume. I stand by 10X’s the power of the lead guitar player. Luckily, watts are pretty cheap these days in the class D world. Going from 300 to 800 watts is not that large a jump if the rest of the features are the same or similar. True that to both... although the OP would find more difference in the tone from different speaker cabs than from different heads. Even though most companies do have a baked in tone to some degree for their heads, with some EQ, you can usually get passed that part. Some do also hit harder and have a bit more authority than others. (The most current class D power modules hit harder than earlier ones). Still, taste is the bottom line when choosing any gear. As for using the PA for FOH, you do want to consider the DI in the head. Most current heads have a DI but some are better than others and some are missing some important features (like a pre/post switch). The best are as good as just about any stand alone DI short of the exotic ones. The upside is that there are tons of killer amps out there at a variety of price points. The downside is that there are so many choices, choosing can be difficult.