Edge and Plat are in the Ascent/ Ascent Premium MR category so an application of either card will trigger the bonus points. You'll have to weigh out the pro/cons of both cards as they differ significantly. By opening one of the account below and merging your Explorer to the Ascent, you are earning 2points/$1 into the Ascent program. There are referral links where you can pick up additional points.
Edge - $195 annual fees, good earn on supermarket (3/$1), 9 airline transfer partners + various hotel partners, $200 travel credit (post March 2016)
Charge - $1200 annual fees, good earn on restaurant (3/$1), 10 airline transfer partners + various hotel partners, $300 travel credit, comp elite tier hotel, lounge access, access to AMEX Fine Hotel for additional benefit.