An R8 507 would be nudging 80-85k I'd imagine? An SSVR in comparison is great bang for buck but at a guess you'd still be looking 75-80k by the time you add the supercharger and all the fruit of a Walky/Harrop pack.
The LSA will allow better scope down the track and should hold its value better. SSVR/Calais is obviously a bit cheaper
If you really want the blower to make some noise then get a Gilmer kit from Enhanced...but overdriving in general will liven them up.
But to throw another spanner in the works, I would keep an eye out for both Holden and HSV limited builds in the run home. Something like the Director would be better than an SSVR or Calais to me personally if the price is right.