Well, I'm going to say it. If I had it to do all over I wouldn't buy a kit. None of them seem to do everything the way I want.
Here is what I would do to start.
This gets you what comes in most basic kits, but you will be able to add on to QUALITY parts as your build continues instead of REPLACING them.
I would hold off on a track bar, but know it will need to be replaced. If you wheel you will destroy yours at some point, but IMO there is no reason to replace it until it's bent or an end is fubar.
3 inch Synergy springs.
Rancho RS9000xl shocks.
Synergy front track bar.
JKS rear track bar bracket(any quality brand will work).
Extended brake lines.
Hockey pucks for front bump stops.
Rear bump stops(whatever brand floats your boat).
Extended sway bar links. Do some research here, you may want disconnects for the front and there are tons of brands out there.
Programmer(you will need to do something to correct speedo, etc.)
Buy each part as you can afford them and wheel it stock until you have it all. You will learn from others what works and what direction you want to go, but I think the things listed above are a solid base to build on.
Next depending on budget I would add front lower adjustable control arms or front control arm drop brackets. Both will help with handling by getting some caster back. You will probably replace the brackets down the road with arms.
Synergy sector shaft brace.
Synergy front upper track bar bracket.
Adjustable rear track bar.(my preference again is Synergy, but there are lots to choose from)
At this point if you've been wheeling you're probably going to start thinking about other things like bumpers, a winch, a better way to tote your bigger spare around, lighting and all kinds of stuff and if your rig wheels & handles well, have at it. You can add the next things whenever and it will just make it work better. By now you've probably already had to replace the track bar, so it won't be listed anywhere(well almost).
Control arms as budget allows.
Ram assist for steering(if you haven't replaced your track bar, do it first).
At any point you can do a raised front track bar bracket and drag link flip(again my preference is Synergy), but with 3" of lift you will be trading up travel for handling. It will handle better, but you sacrifice suspension up travel in the front and it may not even be necessary if you are happy with your handling.
As for the axles I'm kind of a break and upgrade guy. I don't plan to spend shit to improve the strength of my D30. I'll save my money and buy a Dynatrack ProRock Unlimited D44 or Terefex D44. In the mean time I'll buy used replacements from the forum if I break anything(which I have not, yet). If I bend the 30, it's just an excuse to buy the 44. For the rear axle if you have the extra money throw in some better shafts, if the budget is still tight buy a used one from the forum to use as a trail spare until you can afford an upgrade.
Gears & lockers, you will figure out what you want/need as you wheel. I wouldn't do anything until you've wheeled for a while. I have an 07 with open diffs and 4:10's and have never been stuck or not been able to get wherever I needed to. That may be different for you and certainly is for many others, just depends on what your doing with your rig.
There's also a shit ton of other stuff you may want or need as you go, limiting straps, shock relocation brackets,.......... The list is endless, but you will only know things like that as you drive and learn.
Good luck with whatever you do.
I'm sure I forgot something, but the fuckers here will certainly point it out.
Long ass post over.