What should the Rehm-Weller equation look like?
Both expressions are identical. It's just juggling of the signs, since

$$E^{\mathrm{red}}(D^{\cdot+}/D) = - E^{\mathrm{ox}}(D/D^{\cdot+})$$

Relevant primary references would be:


Rehm, D.; Weller, A. H. Isr. J. Chem. 1970, 8, 259-271.
Rehm, D.; Weller, A. H. Ber. Bunsen-Ges. Phys. Chem. 1969, 73,
834-839.
Weller, A. H. Z. Phys. Chem. NF 1982, 133, 93-98.


A normative glossary of terms in photochemistry is available from the IUPAC.