The HVX is basically a SD camera but it does have nice organic color, the EX will be sharper but it tends to have a flatter color profile and I think a kind of yellowish tint. If it were me I would start with the HVX and maybe sharpen it a bit then lay in some EX3 shots and see where you need to push them to match color.
-Rob-
Robert Houllahan
Director / Colorist
Cinelab Inc.
http://www.cinelab.com
MAHC-PRO 6-Core 3X GTX285 20Tb SAS Wave Panel Panny 11UK SDI Plasma.