Need some 101 Education in front Disc Brake conversions kits/lowering kits

[C4UC101969]

Guys I am very new to owning a classic truck that is all stock down to the front drum brakes that are 6 lugs.
I am realizing that I should be changing the front drums to discs and further dropping the truck by 2.5" in the front and not sure about the back this is where I need ya'll help and education please.

I've included some pics of truck as it currently is, my questions are plentiful:
1. Which supplier should I go with?
2. Changing to disc brakes will my front wheels fit on the same way as on drums or will they be pushed out, I have 20x9" with 5" backspace?
3. If the front wheels will be pushed out, do I have to push out the rears as well?
4. Does the rear need lowering as well if I drop it further the front by 2.5"?
5. Do I need a separate lowering kit?
6. Do I need a sway bar and what it does?
7. Will the bolt size change as currently it is 6x5.5?
8. Any other questions that I did not ask(I am sure there are plenty, please let me know what else would be involved with this conversion.

I know it has been talked about it plenty on these forums but it is all over the place, I just want to have it all in one post/thread so to speak.

As you can see from my questions I am not at all mechanically inclined but I am willing to learn fast and my local shop will be doing all the work but I just want to know what parts I need to get him so that everything gets done all in one day without back and forth.

Please any clarification/education will be greatly appreciated from this awesome community of classic truck enthusiasts!