What should I do?

Hello all. I'm new to this board and new to Honda's for the most part, except for my CRX I had 11 years ago . I am looking into getting a civic coupe and doing an engine swap right away.

Can you all give me opinions on what would be the best? Is an engine from an Integra GSR the best? i.e. most HP and all?

I will most likely be adding a turbo as well. So please consider that in your suggestions.

Finally, is there a difference between a Civic EX and Si other than the engine? i.e. suspension, brakes?

Thanks in advance for all of your help!