RE: what prop jet
The cermark jets are about the only decent prop-jets you can buy in the 60-90 size range that are ARF.
Vmar makes a couple, they fly nice - but some have questioned their quality here and there.
The Bobcat pusher (et al) are worth looking at too.
I think VQ has the T-45 available. But that is more 50 sized.
Some of the best flying prop-jets are the ones offered by Juno RC and AK Models. But those are wood kits. Well worth taking the time to build them though.
Bob