Best advise I can give you;
Buy the best parts you can afford. If you can't afford quality parts, don't do it.

Best tools you can afford. If you can't afford quality tools, don't do it.

Best experience you can get. If you have no experience, get someone to help you, teach you, or do it for you.

See a lot of unshootable home brews over the years. It always boils down to the above.