Oceanic is not recently purchased by Aqualung, they are still very much independent companies. Aqualung purchased Pelagic Pressure Systems which was a sister company of Oceanic under the AUP umbrella.
If you want top of the line gear, you aren't going to be going to either of those brands for hardly anything...
DeepSeaSupply - Products
that is the top of the line BC on the market, it's literally that simple, conveniently it is also the best bang for the buck on the market for BC's. Just under $500 and will last you forever, and grow with you as a diver.
Perdix - Shearwater Research
that is the top of the line computer on the market, also a fact. It does not help you eliminate the pressure gauge, but you said top of the line, and none of the AI computers on the market come close. If you are hell bent on AI, then I'd hold out a little bit longer for Scubapro to hopefully announce an AI transmitter for the Seabear H3. It isn't as good as the Perdix, but it has AI, and is a watch size computer.
Do NOT buy a new Scubapro computer right now, their acquisition of Seabear means the whole line is turning over likely at DEMA this fall. Their computers are really overpriced anyway and by no means the best on the market.
Regulators are very subjective and top of the line doesn't really mean a whole lot.
Atomic Aquatics ST1 Regulator
Xstream | Poseidon
I'm tempted to say it's a toss up between these two, but it is a lot of personal preference. Atomic are made in the US to a ridiculous quality standard. Poseidon is the same in Sweden. They are truly top of the line regs in terms of performance. The Poseidon isn't for everyone, but I love them to death and won't trade them for anything.
Scubapro makes some damn good regulators, but I don't like the brand for various reasons, if I had to choose, MK25/G260 or MK25/A700 would be top of the line, but I think overall the Atomics beat them for piston style regulators. Aqualung doesn't really have anything that qualifies as top of the line imho, including Apeks. They're all old designs, and there are better options on the market for top of the line. They are all damn good regs, bulletproof, and are used on some of the most demanding dives in the world, but that doesn't make them top of the line. Now, nothing except the breathing machines can even come close to telling the difference *assuming they are all tuned properly* between say the MK25/A700 combo which costs $850, the Xstream at $600, or the Dive Rite XT at $450, or even the HOG D1/Classic combo that was selling for $200 up until last Christmas. That last one is being used on deep, long, expedition cave dives btw. There are a lot more factors than "the best" that will guide you to a regulator brand, so don't focus on top of the line.