Yes 2.3.3 is the latest but it.is impossible to root the EVO at this time with the ginberbread up date I think might be taking you for ride it says rooted with update stock you cannot root gingerbread at this time hum looks fishy to me I would pass on it
You can have a rooted evo with the gingerbread update. Because it is from eBay with a bid of $1 I wouldn't trust it. Honestly I don't trust anything from eBay.