Author of this thread, before you ask questions like this, you really need to give us much more details on what the f*ck you want? Seriously, your lack of details leads to arguments between us and misguidance to you because we are not exactly sure of what you are looking for. What is more important to you, peak horsepower? If so, then a lot of the turbos mentioned to you will not give you the peak hp numbers you may be looking for and you will be disappointed. Do you want more than 550WHP and stock like spool? Not gonna happend, a GT35R or GT40R may give you the peak numbers you are looking for, but spool will not be close to as fast as stock. Still once the turbo kicks in, WOW!

Or is spool more important to you? If so, then turbos like the 20G, GT3071, TME, and even the White Rabbit are for you. These turbos can make very good power and offer much quicker spool than the larger turbos. Still they will not match the peak power of the larger turbos.

How much power are looking for? 400-500WHP? 500-600WHP? 600-700WHP, you did say no spending limit? Remember you will have to sacrifice something to achieve the other, meaning if you want big power, then you will need to sacrifice a little spool, and if you want quick spool then you may not make as great of power as you are looking for. There are in between turbos such as GT30R and 50 Trims which can make around 500WHP and have quicker spool than the larger turbos, but something tells me, you are looking to make a lot of power. If so, then the GT35R or GT40R turbos are for you, they will make huge power, but you will sacrifice some spool quickness, but still when the turbo kicks in you will be loving life.