Most 60 cm CSIs are going to have a 60 cm TT vs. the Zanc's 59, so there's that. You should be able to find a CSI frameset for much less than $1200. I paid somewhere under $500 for mine. There's a nice 63 cm CSI with 60.5 cm TT on ebay for $1400 shipped, including a nice Chorus/Record 9 build. Only fault I can see with it is that the fork is an AlphaQ rather than a steel Serotta.
https://www.ebay.com/itm/Serotta-CSI...oAAOSwydpZepL0