It'll be at least a year before any genuinely better games come out, these early ones may have a little graphical tinsel, but there's nothing as good as Gta V gameplay wise. Better to wait, the prices will come down, chipsets improved, problems ironed out.
Pegassi is Lambo. With a Ducati bike division. They don't have any McLaren cars. The Vacca has MP4-12C air intakes, but that is all.
The Monroe is a Lamborghini Muira. The name Monroe refers to its famous appearance in "The Italian Job" in which a Matt Monroe song is playing during the scene.
The Infernus is a Mercialago, with a bit of Diablo thrown in. The exhaust is Pagani Zonda for sure.
The Vacca is a Gallardo with MP4-12C cues. The name is spanish for cow, referencing the fighting bull that the Gallardo is named after.