Ok let me explain: The ASG-1 is one product and the 1.2 is a revision of a current product, it is still the ASG-1 and it doesn't really need a new model number or designation.
About your second question, I'm not too sure about which you're asking about so I'll tell you all I think that may be the answer:
- There are reviews all revisions (1.0, 1.1, and 1.2) usually the review will say which revision is being reviewed.
- The customs we generally talk about is the "b" version and not the AS-1($399). The AS-1 is the same as the ASG-1 except it's custom. The AS-1a comes with an ambient port so you can let in more external sound (+$100). The AS-1b version everyone talks about has the ambient port as well as a bass port for adjustable bass(+$200). There is also an AS-1c which is the cable down configuration (+$50).
Hope this answers your question