I think there are two ways to do this, replace DVD drive with an SSD, or add a second drive behind the motherboard? I was wondering if there was a definite advantage to one or the other?

Does the DVD bay support same speed connection as the hard drive bays? I imagine if not that might be one reason to add it rather than replace DVD?

What size SSD would be optimal, is 250GB enough or is there enough to be gained from 500GB to justify extra cost?

As the hard drive is five years old, would anyone think it wise to replace it at same time?

Finally (sorry if this is too long a series of questions) is it ok to do a full restore or would I be best to have a fresh O/S and just restore photos / music etc. and re-install programs?