The first two are already in print, as Two for the Money, from Hard Case Crime. The other six have been hard to find for awhile, but will be out at some point this year from Perfect Crime Books, who also reprinted the entries in MAC’s Quarry series that aren’t available from Hard Case Crime.
Golly gee, I’ve got a lot of reading ahead of me in the next few months. I just got the lost Donald Westlake novel, The Comedy is Finished, and I just ordered the second volume of Sand novels from Ramble House. (MAC mentioned in the comments at this post that Sand was also an influence on the Nolan series.) More to come on all of that. For now, time to stop typing and get to reading.