Kyosho will be releasing the 777 SP2 kit in August and an upgrade kit in late June/early July. SP1 kits might get cheaper soon knowing that. As far as I know the standard 777 kit will not change. Since you are new to 1/8 I would recommend either of the Mugens or the 777 SP1 or SP2 (when it becomes available). If you get a Kyosho you will eventually break a steering knuckle. You can get machined ones from several sources or the stock ones are really cheap. Unfortunately a broken steering knuckle often takes out a caster block which is not cheap. The stock ones are pretty strong as long as the weather is warm. I would replace them every 2-3 gallons for safety unless you go with the machined ones. You will also need to get a set of standard diff gears, cross shafts, and pins (about $12) to convert the front diff to a standard setup instead of the stock LSD.
The Mugen Pro-Spec has all the hop ups you will ever need for that car but it is expensive. A standard Mugen kit probably needs a front shock tower and a steering plate.
Get Craddock or Fioroni brakes for any of the cars you listed.