Am i the only one having trouble reading this...
Got to admit it's getting a bit tedious!
Basically the 8v is not a tunable engine at all, a remap is pointless and a cone filter may sound better but will do absolutely nothing for performance. If you want to squeeze a couple of extra ponies out of it then give it a really good service, stick on a stainless steel exhaust, put a panel filter in with a cold air feed and you may see an increase in power.
Alternatively you could change the camshaft and run more aggressive cams, Khare saw about 138bhp with a Kent Camshaft. A remap would also be beneficial if you do this.