Imo if your weighing down to .0001 of a gram you need to be annealing every firing, uniforming flash holes and weight sorting your brass to the grain. Personally I just use a powder measure or a chargemaster and call it good enough. A beam scale is slow but accurate on a budget.
I would not get that kit you linked. Get a rock chucker kit instead. As far as getting into reloading $1000 is just a start. If you shoot a lot of volume and have a lot of free time reloading is great. If you shoot very little and are always busy it will be a waste of money. The cartridges...
Those two bullets you mentioned are much shorter than a 75 eld. A 88 eld is much longer than a 75 eld and would most likely require a 1-7 twist to stabilize in a 223.
53 vmax 50 vmax 55 vmax 60 Sierra tmk are all excellent bullets. Your H335 powder is fine but if you want cheaper alternatives go with Xterminator or Tac.
I think what your seeing at midway is the stag 5.56 for that price. The 308 is $1550. If he wants to be in the sub $1000 for a 308 it’s going to be a gamble on quality.
Athlon OpticsHelos BTR GEN2 2-12x42 AHMR2 FFP IR MIL #214105
From camera land would be a good choice. Make sure to call and ask for a better price.
Also some good deals right now on Trijicon Credos at eurooptic. 2.5-10 for $520 if you want the second focal plane.