Where can I get a surplus USMC lwh? Thinking about getting one to go with all my other military stuff. I'd like one around the 2004 era. Looking for one with the tri color desert cover. I don't know anything about helmets so bear with me. Thanks!

eBay, but it's just easier to just get a PASGT.

If you are dead set on the LWH, you will most likely have to pay the price unless you score one on eBay or you can fit into a small (and I do mean SMALL) helmet.

What's your price limit? Does size matter? Getting the cover is no issue, any PASGT cover will work and they can be had for about $5 to $10. 

It kinda sounds like this is just for a display or collection. If so, I'd recommend getting a PASGT instead. They're cheaper and much more common. Unless of course this some sort of display of a Marines gear and you need it to be accurate.

LWH are rapidly declining in price, due to the fact the Marine Corps is phasing them out for combat use in favor of the ECH (IIRC) and right now relegating them to training use. Also, no one really wants the the old PASGT cut style helmets, opting more for high cut HSLD types.

If you want that helmet cut, I'd say save up and pay a little more for one. Their comfort exceeds that of the PASGT by miles just based on the improved suspension alone, plus the weight reduction.