Oil wise you should already be running a fully synthetic oil such as Castrol SLX or Castrol RS, Mobil 1 etc etc. If you're not, then change it!!
DV wise - the original ones are rubbish. The Forge 007P is one that is commonly used on this site.
Air filter wise - one of the Green replacements is advisabe to
help the engine breath. Whether you go for a panel filter and then improve the air feed to the air box, or go for a full kit like the Dynatwist is your choice.
Obviously you should know from reading the manual for your car that super unleaded is the recommended fuel for the engine. The fuel that I have seen the best results with is Shell Optimax.
Different ecu mappers get more from the car in different ways. On the LCR's, REVO had higher torque figures, but an overall shorter rev range. Jabba had lower torque figures, but produced max bhp slightly higher up the rev range. I don't know if this is still the same of the 180bhp engines...
Jabba's boost controller will adjust the boost from the new "Jabba" boost level down to slightly below what is standard for the car. I actually found that having the boost turned down made the car a lot smoother than it was as standard!
Further improvements can be found by changing the DP, CAT and exhaust.
If you spend the cash, with improved induction, front mounted intercooler, upgraded downpipe, race cat and free flowing exhaust, I've seen Octavia's producing near 250bhp - the power's there to be had!! Just depends how deep your pockets are!!