They are two contradictory demands generally, and further apmlified by the fact that you want to run low pressures off road.
Serious CX racers run several different types of tubular tyres of different tread patterns, depending on conditions, and run pressures as low as 20 psi. In clinchers that will lead to pinch punctures, so you'll probably want to run 30psi or higher if risk of pipnch punctures is high. The pressures you run have a greater bearing on your grip than the actual make of the tyre. Highly rated tubs come from the likes of Dugast, FMB, Challenge or Tufo.
I would persevere with your tyres for now, get more off-road experience and experiment with lower pressures. Once you feel you want to commit to spending more money, have a look at other tyres available, but TBH with clinchers you will always be bouncing off this pressure limitation.
If you really want to buy new tyres, look at the Schwalbe Racing Ralph's - that's a decent clincher. Having said that, in truly muddy conditions I get about 50% grip with those as I do with FMB Super Muds at 20 psi.
