It's not rocket science but yes, it's always best to deal w/ someone that knows the cars intimately
I agree that the front shock is probably a Koni, The only ones i'd recommend are the sport versions which will have an adjustment knob at the top of the shock
The yellow Bilsteins are likely Sports, if so the specs are 311/160 which is quite aggressive for a stock suspension SC, the regular Bilstein HD(green) are 195/151
the specs are x10 N at .52m/sec
JMO but fo r best results the same Brand shocks would be used f/r
Bilstein HD/Bilstein HD is what was used on 930
some guys w/ more aggressive setups(me) use Bilstein HD/Bilstein Sport, but there is a lot more suspension development and refinement to be done before I'd recommend that for every one. The icing on the cake for a really supple yet really well controlled ride is to give the Bilsteins a digressive revalve.
But starting w/ fresh bushes is a very good first step, there are essentially 4 levels of bush to consider, the last 2 are mostly track only so forget them, What's left is stock rubber or stiffer sport rubber, which to use depends on what type of ride and use youa re going for
As Flow jo syas you can also use 21mm rear wheels spacers , there are some advantages in handling to wider track front and rear, just doing so in the front induces less understeer which is generally a good thing on a stock 911, +21 at both ends will raise grip levels at both ends and restore stock handling traits, that said in general it is far better to used wider wheels and tires(while keeping tire OD as low as possible)
Here's a chart of suggested SC/Carrera wheel/tire setups
