lol I'm willing to bet you have the fastest GTR in town.
Anyway, on topic, $uperlap is a once a year event with super $$$ cars. Looks like bad value for money to me.
If you are serious at giving it a go you need to work with someone who knows how to prepare a gtr - bolt ons, no matter what brand or price are not going to get you close. for example, the top local cars this year were all supported from an engineering view by one supercar team or another.
Looks like you have sufficient power sorted, so all you need is a fully custom suspension setup, huge weight saving and custom tyres straight from the manufacturer that other competitors can't buy. Oh, and a professional driver. Then you are a shot for top 10