Hi Andrew, welcome to the YOC, it all depends if you want to go resto ie back to original or just something that works. One suggestion tho, buy something that they made a lot of, that way the parts are out there, not like trying to find the axle for a 1926 Scott Squirrel for example! Don't be fooled into buying 2 of something thinking you can rob parts from one to make a good one either, if they are the same year and model then it's a fair bet that the worn (fucked) parts on one will be worn (fucked) on the other as well. Decide if you want 2 stroke or not, a lot less work getting a little 2T going than a 4T with all the gubbins they come with.