That Nishiki is a good deal for $100 the wheel crank and chain are worth that alone. It would be more of a lateral move than an upgrade but go check it out you might like how it rides over your Vilano. The other frames are not really worth it unless you want to build them up and try to sell them. I just picked up a complete rideable but rusty with bad tires, Schwinn like the gold one for $10 yesterday. They are going to be pretty heavy and have American sized bottom brackets (bmx, one piece cranks). Origin8 cranks aren't too bad they are a good entry level part. They are made by a company called Lasco and Origin8 puts their name on them.