I hope this is the right place to post a few general questions relating to these pre-amps.

Can anyone enlighten me as to the difference(s), if any, between these two pre-amps, please ?
Would either of these be equally good additions to a system or would I be better advised looking specifically for one of them: And what should I expect to pay for either/or the better of the two, in reasonable un-modified condition ?

Thanks in advance and I hope you don't mind the dumb questions.