I hope I ma not to late to the game. I have built every PC I have since 1996. However, I will say right off I am an AMD "fanboi". So all of them have been AMD. ( my last Intel was a 486SX)
Building PC's even gaming rigs is very easy, and to me loads of fun. First off .. lets drop the third option as it use the APU. An APU is a combined CPU and GPU, though if the unit is to be a "throwaway" it may be ok. I prever to have a real CPU and then buy a GPU, which I upgrade more often than I do CPU's.
I would also say that the uses you listed are NOT for a weak system!!! Vid editing is a special case and CAD is as well. You did start by stating the most important thing first.. how you will use the PC.
I LOVE Newegg, and 100% of my PC's.. TVs, cameras and all things electronic come from them. That said ... I do notl ike nor trust their combo packs. AS you can see the savings are not that big ( $60).
A good start would be be with looking at what your software NEEDS and wants. Get enough ram and enough GPU (GPU is video card). Then choose a flavor of CPU ( Intel or AMD) them find matching memory, then size the PSU ( power supply). Pick a case you like. My case is now about 10 years old and was $80 back then. Now they are $50... and its still a hoss of a case. Also by picking parks one at a time and watching for sales I am sure you can beat the $60 for the combo.
That leaves drives. I am no longer a fan of internal CD/DVD drives. They just are not that useful and prefer to have an external ( USB) DVD burner. Then I like to have a GOOD but not too big main ( aka C) drive. Personally I still use the old spinning platter aka HDD, but many are happy with a GOOD quality SSD ( soilid state disk). Then I get second internal drive for data... and in my case a third drive ( SSD) for programs. Yes that is three drives ( 4 with the DVD). The slowest point for any data is from disk (esp. HDD). So by having different types of data on different drives this speeds up overall performance.
Drives:
Main drive HDD or SSD of 240GB to 500GB
Program drive SSD 60GB to 240GB
Data drive 800GB to 3TB
Do not use an extrenal (USB) for data as it is wayyyyyy too slow.
In my case:
Main drive: WD Raptor 300GB ( this is the fastest HDD around 3.5 format
Program Drive: Kingston SDD Now 60GB - cheapest SSD, but so what it is dies I only lose program data which is sitting on a DVD somewhere anyway
Data Drive: WD red 1TB 3.5" A newer drive by good ole WD
Note: Video editing needs a drive that does not interrupt writes, as most HDD do. WD (and others) make SPECIAL drives known as AV drives that will not interrupt the writes. ( I think WD calls them purple)
PSU- pay extra and get a GOOD one. Watts do not tell the entire story. I bought a 450 watt PSU that had all the Amps on the CPU. Leaving only about 80 watts for the GPU and HDD. It was a gimick. The PSU was no good for anything. Personally I love PC Power and Cooling. Mine is 750 watts. It has and will drive 4 vid cards... an 8 core CPU and 6 HDD all at once!
Memory.. it use to be that anything over 4GB was kinda wasted and VERY expensive. Not anymore with 64bit OS newer programs are starting to use the larger memory space that is offered. 8GB is not too expensive and 12 or 16 might be useful if your CAD program use it.
Now have FUN!!!!