Longevity issues aside, I don't think any tire made for Valk sticks better in all weather and on painted surfaces than the ME880 (42-3 psi front) (and my boards are beat up on the edges). And the fronts go a long way (as you note, about two rears). During the two years or so Metz offered the promotion, I ordered two rears and got two fronts for free (and shipping). When the last Metz rear goes, I'll have two bikes with Goodyear TT rears and Metz fronts.
I thought it might be interesting to try a different darkside rear on the 2d bike, but as I am a darkside newguy, I suppose it best to have the same tire for consistency.
Otherwise, an Altima HP.
http://www.tirerack.com/tires/BigPic.jsp?sidewall=Blackwall&tireMake=General&tireModel=Altimax+HP&vehicleSearch=false&partnum=06HR6AMAXHP&fromCompare1=yes&place=11