If this is your first build, there’s so much sportster stuff out there that’s new that will give you an old school look. But I would say avoid a used springer front end unless you know what to look at on it also avoid locked up fork front ends unless you want to bash your head working on breaking them loose and cleaning. I wouldn’t go buying overly rusted parts because polishing can take the fun out of a build unless you like it crusty. Don’t buy trashed spoke rims thinking you’re gonna re-lace them… personally I know the difficulty of cleaning rusted oil tanks and gas tanks. It can be easy sometimes it can be tough with pitting or holes. Unless you’re working with a full on, well equipped shop and have tons of knowledge, buy parts based on the tools you have to work with, in getting those parts to where you want/need.