I’m just trying to determine if the potential for handshake issues (however remote) would still be present with DVI on the monitor end or those concerns would basically be non-existent.

Mini DisplayPort to Dual-Link DVI adapter According to a customer notice forwarded to MacUser, Apple cites an “unexpected delay” and apologizes to customers for “any inconvenience” the ...

The adapter sells for $29. If you want to connect to a DVI display, you can use StarTech.com’s Mini DisplayPort to DVI (MDP2DVI) adapter. It supports video only and is priced at $29.

Display port, however, would work. If you can't get the version with a displayport input, then to run both at 144hz you'd need an active displayport to dual-link dvi adapter, and those aren't cheap.