Rebuilding 97 Riviera

[Sigsmaster]

Hey everyone
I’m ready to have my 97 Buick Riviera rebuilt. I love this car, loved the new style of Riv from the first time I saw/drove it. Its super charged and has 188k on it and it is worn out unfortunately. If you read some of my old posts I have been dealing with a chronic stumble miss for many years with no one able to figure it out. Now that money is no longer a problem I want to get the engine not just running like it was new but better.
I have read some great posts over the years of members building some great cars. And I need advice through the process.
I want this thread to be the process and advice over the next year or two. From a functioning conveyance to a sleeper that will scare the **** out of me.
My plan so far is find a great garage and get the engine done. Then move onto transmission, then suspension and exhaust, then interior and finally exterior.
My first question is what can I expect to pay if the engine including super charger needs to be rebuilt? $1500? $3000?
Tell me what you think of my goals and process. Is 300 hp or maybe more unrealistic? Thanks ahead of time.
Bryan