Hi Nathan,
Welcome! I'll let others talk about the specifics of the gear, but have you thought about how you might travel to a dark site with it? Unless you can find a site with power, you'd need a generator or deep cycle battery plus quality charger - neither are particularly cheap.
Here are a couple of example pics to give you an idea of why it's worth traveling to a dark site... the light polluted version was taken in my backyard in Brisbane (Rochedale) - a stack of 52x 185 second exposures, for a total integration time of 2 hr 40 min at f/5.6. The raw subs are basically a sea of pink light pollution, and the final output still has a gradient that I haven't removed.
The dark site version is a single, unprocessed 15 second exposure at f/2.0 (equivalent to 2 min at f/5.6).
Let's just say I won't be doing any more imaging at home!
Cheers,
Dave