Spark Plugs? Oil? Clutch? Gears? Sensors?

Here is my situation, I have a Rover 214 (head gasket has just been redone) and for the past month when I am driving the temperature is what it should be the rev's are normal for the speed, but when I accelerate (usually from 1st or 2nd gear) It feels like I am going up a steep hill, just like the power has been sucked out, like when you turn air con on and you feel the power drain, so I am asking what the most likely cause is? could this be caused by spark plugs? or could it be low oil? or could it be worse like Clutch, Gears or Sensors? Please help.Spark Plugs? Oil? Clutch? Gears? Sensors?
Have the transmission checked.Spark Plugs? Oil? Clutch? Gears? Sensors?
It sounds as if the fuel delivery system has been compromised. Fuel filter and fuel pressure should be thoroughly checked as well as a complete dealer fuel injection cleaning.