If price is your main deciding factor, I'd factor in how much the Kemper will be before deciding on your FRFR setup
Getting a passive Gemini 1 and a crown xls power amp will cost you $850 via Reverb and eBay atm. Getting a powered used Gemini 1 will cost around $1100. If you can find a great deal on a powered Kemper (Under $1800) use the difference to just pick up a passive Gemini and call it a day. If you find a great deal on an unpowered Kemper (under $1600) pick up that power amp and passive and you'll still be in business.
There's a plethora of options you can choose regarding solid state power amps but try to find one that matches the speaker output as close as possible (also never have the power amp output be less than the speaker output).
When it comes to pro/cons of passive vs active:
pros for passive:
-price
-more headroom
cons for passive:
-requires separate power amp
-harder to find used
-spec checking to match amp output to speaker output
-needing to transport two things vs one thing
pros for active:
-no additional gear needed
-plug and play
-empower knob (gemini feature)
-bluetooth (gemini feature optional)
cons for active:
-more expensive
-not as high of headroom compared to passive
When I mention headroom I'm NOT speaking on loudness because both of these units can get quite loud based on the reviews and vids I've watched. I'm literally speaking on how much you need to crank the master knob before sitting at a good gigging volume without any distortion. I don't believe that any of these options drastically suffer from high volume distortion anyways so I guess that isn't a major worry factor here as well, but I figured I'd mention it at least.
Hope this helps @blandified