My conversion write-up: http://forum.saiga-12.com/index.php?showtopic=31499
Whether to you purchase one already converted or you do it yourself is completely up to you. No one else can tell you which is more viable for you. Forget how much time, tools, money you have, #1 question you should ask yourself is do you enjoy doing the work?
America is great. If you don't like doing something you can always find someone else who will take money to do it for you.