The latest models are all much of a muchness! I think you will find the protection levels are all pretty similar, just comes down to the one you prefer and fits the best for you. I have an Alpha 200 and have no plans to replace it other than putting an ANR kit in it soon. Don't buy second hand, get a new one with a decent helmet bag and look after it.
You might find one day that you are pretty glad you choose to wear one...