If by pre-ban you mean pre-1986 look at:
www.subguns.com
www.sturmgewehr.com
www.uzitalk.com
www.ar15.com
But be prepared to spend ALOT of money. The basic entry level MG goes for about $3000 now. Also your state has to allow possession and you have to jump through all the federal hoops as well. It's not easy to send thousands of dollars to someone halfway across the country and then wait up to 9 months for the fedgov to do their thing before you can even put your hands on your new toy.