This is a slightly tangential point, but....
Getting hung up on your potential system 'feeling like a real organ' may not be as productive as you might expect.
1. Real organs vary tremendously. An historic mechanical action, a modern mechanical action, a 19th century pneumatic action and an electro-pneumatic action will all feel completely different. It's quite likely you will want virtual representations of all of these on a single hauptwerk installation, and clearly you can't even attempt to simulate the feel of each of them when they are so different.
2. Hauptwerk isn't a 'real' organ. Barring a ludicrous amount of effort and expense it won't feel like one. But it can be very satisfying nonetheless.
3. I'm personally unconvinced by any 'tracker touch' keyboards I've encountered. I've played new tracker actions, old tracker actions, pneumatic actions etc etc, and IMO the only type of real organ mechanism that can be properly simulated by electronic keyboards is an electric/electro-pneumatic one.... Which isn't really a simulation at all because Hauptwerk is indeed inherently electronic, and that's OK.
4. You don't play an organ with your fingers, you play it with your ears. Even more so with Hauptwerk.
I use modified Beringer consumer grade keyboards and I'm quite happy with them. Truth be told they're preferable to many 'real organ' keyboards. They are not the last word in quality, of course. But it depends how much money you have and how worthwhile you think it is to spend more.
If money was no object I would do an initial set up with cheap keyboards, then look to source keyboards from suppliers to the pipe organ trade. If you want to be slightly more prudent it comes down to try before you buy, and choose what you're happy with.
One more tip - don't buy a cheap pedal board. Cheap keyboards at least benefit from economies of scale in production, but pedal boards...... You need a decent one - a second hand one off a real organ can be a good choice, or be willing to pay for a good new one.