need professional help

ok i have a 1994 jeep grand cherokee laredo auto 4.0l inline 6. the only mod i have done was took out the air box and made a getto performance intake that sits on to of the throttle body (really short ram intake). my oil problem is horriable. to give you an idea of how bad if i refilled it up with oil to the safe point less then a month later it would be down way past the add mark.
ive never seen a stouter engine than this one. ive ran with almost no oil on the dipstick and it still runs fine its insane. i cannot keep refilling it up like this. this oil problem has literaly fould all 6 of my plugs.
i replaced all the founed plugs 4 months ago and it did great now i might need more plugs it feels like i need more. my dad says the valve seals are shot to hell and others say i blew a head gasket. my question is what the hell could it be? if im sitting at a red light for a long time i then go my car bill bog down like hell and while its boging down it smokes white like hell.
i found a way to not make that happen by putting the jeep in neutral and reving it up to a little bit above idle that helps it not do it so much. secone i know when im gonna burn oil by my engine when i start it up the valves will knock really loud for like two seconds and also knock when it bogs down. my dad says i need either a head rebuild or replacement. the jeep has 130000+ miles on it and the transmission is also slpping at 19mph.
any imput will be awsome thanks guys

I would guess its the valves. For the clue u gave of the white smoke. I had a truck that did white smoke at the begginning then blue/white smoke. Turned out to be a cracked head. Cracked in 2 spots I come to find out. You got some serious problems here. I would pull the cyl head and check for crackes, then replace headgasket. But if I were you I would pull the entire engine and just rebuild it. It will cost abit more, but well worth it in the end.

White smoke, humm coolant getting into the combustion chamber = blown head gasket. ussually a blown head gasket would be at a certain point (like between 2 cylinders), do a compression check on each cylinder, this will deffinately let us know what exactly your engine it doing and then we could tell you more... try to post the readings of each cylinder, this would help greatly.