Welcome to the forum. You've come to the right place for answers, advice and help with your project. To answer all of your questions, all of which have been asked and answered many times, can I suggest you use the Google Custom Search feature at the top of this page. Just type in a key word, like 'chain tensioner' and you'll have pages of discussion to read on that one subject. Same for 2 stroke verses 4, in-frame mounting, rack mount, chain drive, friction drive and on and on. There is a lot of information here from many experienced builders. Naturally, specific questions you might have during a build will be addressed quickly. Good luck. Keep reading and let us know what you decide to build.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"