2:46 is a good time for an STI with that few mods.
I'm looking to achieve a decent 200-220bhp at the wheels from a 1.6litre motor on normal 98 fuel.
200-220 wheel hp is approx 240-260 crank hp. Divided by 1.6L you are looking at displacement specific outputs of 150-160hp per litre. This is approaching Touring Car territory. IIRC they run 99/100RON fuel. Formula Atlantic engines at 1.6L making 250hp, run CSP as a spec fuel (108 RON). These are engines that afford teardowns every few hundred miles, and considering that Malaysian 97RON is what you'll be running at the track most times if you want convenience, I think you will have to compromise on your desired output if you want something that will last at least a couple of thousand miles. Remember that freshening an engine of that spec is not even an option in Singapore.
Your requirements preclude building the engine in Singapore. You will have to get a crate racing engine from a foreign country. Singapore does not have equipment of the right specification much less the machinists to operate them. Assembly is possible, but still doubtful. There are people who will read this and privately try to convince you that I'm dumb/ignorant , but just ask them..
1) Where their file for build sheets on engines they've built in the past is. There will be none. Ask for a photocopy of a real sample page. They will not have one, and if somehow they do, specs will be incomplete/wrong/imprecise.
2) How they expect to do flow testing without a flow bench. There is no flow bench in Singapore.
3) How they expect to repeatably mechanically and thermally load a race engine, swap parts out for quick r&d, know actual crank power without an engine dyno. There is no engine dyno in Singapore.
4) What cylinder wall surface profile they run and what hone and grit (process) they run to arrive at it.
So when you coming back to Singapore? Perhaps we could work on a track car together!
Man I wish I had met you earlier. If this had been 2 years ago we'd definitely be building a car. I was looking for a good partner, but never found one. But seriously, I'm not returning to Singapore anytime soon (3 years or so - very possibly more) and even if I do sometime in the future, I would not have access to the right equipment to build a true race spec engine. I will only be at my current location and have access to the facilities for another one and a half years, afterwhich I seek employment here. I probably will not have time for personal projects then.