100W head as a Pre + Poweramp question

Hey TB, it's me with yet another question regarding my faithful little GK.
I recently bought a 210 cab, went with a Harley Benton and it sounda great but the tiny 210RCB is way too underpowered at just 100W into 4ohms, even less, the cab having 8ohm impendance.

So I'm looking into getting an iNuke 1000 to use as a poweramp. I don't need as much power as it can provide so I'm cool with it being overrated. I would like to reach somewhere between 200 and 250W.

The questions are:
1. will I need to bridge the outputs and how is that done?

2. do I use the speaker or the line output on the GK for connecting with the inuke?
Common sense tells me line out, but something keeps me questioning if it's maybe made to handle a powered signal and just reinforce it, meaning moore power!


Thanks!

 

Thanks for the help!