Re: Hello from PA, USA!
Welcome to the forum. It sounds like you've got an itch that needs some scratching. You came to the right place. Good that you have access to nice tool/machines and can weld which puts you in a better position than most of us here. Unless you're absolutely set on the bike you have, I'd spend some time wandering around the site some, looking at other people's builds and reading about their experiences... you might decide on something you like better. I'm not familiar with the bike you mentioned and a 1990 bike is what I call new. I like the stuff from the 50's and older. Feel free to ask anything you want. Lots of good and experienced people here willing to help.
Someday when I grow up I will probably lose interest in toys with wheels, but until then...