Most of them are model specific, so if you're looking to replace it, just search for that model.
I'm wondering if you have figured out the answer to this as I'm having the same problem with the CECH 4201B. It's been a pain so far to find anything.
The laser you are looking for is available at Ebay.I think it is thru ET-Game-Supply. Just search on cech-4201b laser. However it cost 70 dollars which greatly increases your repair cost.Have you had any luck finding the lens piece? I'm currently unable to find one