Comparing £ to HP you think that cams are better than a lower collector? Lower collector is roughly £250? and cams are rougly 3x that amount - before labour naturally
Also don't forget that the HKS kit comes with its own oil supply & oil cooler & I believe cookbot already has an engine oil cooler Stock brakes are ok on a road car IMO, my car held up just fine on stock disks & pads and cams are a bitch of a job as are headers. Stock headers are also pretty good, certainly good enough to flow 400+ hp & definitely well enough to justify keeping them over the cost of a 10 hour labour bill just for install alone - the only reason I did them was because of the retarded cheap deal I got on them
Lower collectors are also not designed for the DE cars which is why Nurrish never used one