Sprint HTC Hero :: Sync Contacts With New Gmail Account

I recently had my phone replaced due to the dust under the screen issue. When I set up my new (refurb) phone with my gmail account, I had tons of contacts in my phone that I had never seen before. The girl at sprint said it imports all of my email contacts, and it looked like they had added contacts from email addresses I had only emailed once, that werent even in my contacts group on my email. They ended up wiping my contacts and transferring them over from my old hero. She said I should create a new gmail account, and use it ONLY for syncing my contacts, that way I dont get all the other email contacts in my phone also. Im wondering how I do this, because I want to set it up before 2.1 comes out for the hero, so when I upgrade to 2.1, I wont have the same issue.