Windscreen angle rarely makes an appreciable difference. The Ceres does appear to have a gentler angle on the rear window, though, which may perform a bit better.
Get whatever gets the best hwy economy stock, then aeromod it. Rear window angles can be solved with a well-done Kammback, but if you start with a gas guzzler it's harder to change it to a gas-miser (but you know this).
Looks like E100 Corollas were offered in 2.0L diesel form. Might be worth checking out.