I assume you mean by 1.8 you mean the 1800 Zetec bottom end so the dipstick is at the front of the bay?

I would have suggested changing the T2 for a larger T3 as it's a shit load cheaper and opens more scope for tuning than the more expensive T2. Unfortunately it seems you have allready got the T2.

First port of call will be a decent exhaust (Magnex, Scorpion etc) and a quality air filter. After this add a chip (although with the ZVH a proper chip mapped to your car would be better).

In all fairness it's more a case of how far do you want to go and how dep are your pockets? 200bhp is a piece of piss, 250 isn't too hard and even 300bhp is achievable.

Don't forget to sort the suspension and definately sort the brakes as the satndard stoppers are pretty naff for stopping a standard car never mind one with a 50bhp power increase