You sound like you're new to forced induction, and possibly the automotive world all together (or at least the engine part of it). So I'll throw out my opinion.
You shouldn't even THINK about turbos until you have a good understanding of how internal combustion engines work, the quirks of a naturally aspirated slant and what they like, and then you need to understand what a turbocharged system needs.
Also ask yourself a few questions.
Do I want to spend weeks tuning this engine once I get it built?
Am I comfortable with multiplying the odds of destroying my engine?
What do I want from a turbo slant that a n/a slant or v8 doesn't offer?
Am I willing to spend $3k on an engine that has high odds of blowing up?
Am I willing to pay more for parts because slants are less popular?
What is the most powerful/fastest vehicle you have drove/ridden in?
What kind of power are you expecting?
What kind of budget do you have for this project? (other than 'Im not a millionaire')
Are you comfortable with either standalone fuel injection or heavily modifying carburetors?
Does this car have to be reliable or get good fuel economy?
How well are you at science and math?
Etc.
There are many people that have tried to build turbo slants, but there are few that I would call successful.
