Around the 150whp is where the stock injectors are about done, they say.
But there are ways around that, higher fuel pressure. But that has drawbacks too and doesn't raise the bar much. But it's not like you're always making full power either.
Cams, exhaust and good suspension makes for a pretty fun car. And that's about as far as $1,000 goes.
Don't "think outside the box".
There is no box.
Do it correct, or do it twice.