How do I match motor and battery leads on a generic e-bike conversion kit? This is for a "Generic Add-on Motorize Bike 48v 1000w 26 Inch Front Wheel Electric Bicycle Motor Conversion Kit."

How do I find connectors to the motor and battery that are compatible before I buy them for this bike? I am not talking about voltage or wattage. I just want the connectors to fit without splicing.
Based on the info you've presented, its "cross your fingers and hope"

Can you tell us anything further about the motor, motor kit?  Even a manufacturer could help.

My ebike kit used 7 pin DIN connectors with a screw-on barrel lock ring.  The battery connectors were generic automotive spade connectors.  

If you're choosing a connector, then voltage and current (ie wattage) is relevant, as is whether you want to hot-connect them.  Plus you need something that is water resistant and vibration tolerant.  (note spade connectors are neither of these... guess how I know that!)

Final thought - you're talking about a kit.  In my mind a kit comes with everything you need to do the job, possibly excluding batteries themselves.  However any parts not included will be common and well-described.  

And what's wrong with a splice?  A properly-done connection will outlive the wire.