Now since I have my frame made, I can think of adding suspension or not. I need suggestions and answers ASAP
Personally if I could do it over again I would not do suspension on my first kart, however, it did provide me with a lot of experience using my angle grinder cutting stuff off and redoing it.
Depending on where you plan to ride it, a swingarm rear and a leading arm front is easy to do, and if you don't need articulation, works great. I'll link a video with both of my karts that I have done so you can see the difference between the single A arm front, and the leading arm front.
http://www.youtube.com/watch?v=kooTzawQaEE
http://www.youtube.com/watch?v=UCOiwtCrt8o