Looking for a $800 - $1500 used high powered integrated with sub outs

I loved it too

and it totally transformed my friends system

Love the Rogue Cronus Magnum.  Great piece to build around.  Enjoy. 

my friend ended up going with a Rogue Cronus Magnum tube integrated.  He couldn't be happier

any Parasound? Joulida?

Try something from Marantz. A used PM15S2b would be nice. It powers my 95db Clearwave Duet 6 monitors to lease breaking levels and has pre out jacks for a powered sub.

All the best,
Nonoise

Check out NAD offerings.  

"My friend recently bought a JL Audio F110 subwoofer. Even though his 15 year old integrated has pre amp outs he tried to connect it and JL Audio said it's a no go."

I find that odd that JL would say that.  A 15 year old integrated with L/R preouts connected to the L/R inputs of the F110 using the low pass filter of the F110 should yield fine results, though not necessarily ideal.  

Now after reading the specs on the Soundscape 8's and them being close to full range with a 25Hz bottom end, JL may be cautioning because of a probable bloating down low.

"Yamaha AS-2000"

I agree that the Yamaha would be a good choice but it too only has L and R preouts and no sub out.

Maybe your friend could find himself a Paradigm X-30 crossover which has the option of using it's high pass filter connections and just keep his older integrated amp.  They usually sell for $125.00 to $150.00 on the used market.  If you can find one.

Bill  

Yamaha AS-2000