Supernews will i am told, i use it on 30mbit without problems and here is the offer link.
Supernews is a Giganews reseller for your information.
$9.99 a month or $99 a year.
http://www.supernews.com/super-special/
OUR USENET PLAN INCLUDES:
UNLIMITED Usenet – No GB Limits
UNLIMITED Speed – Over 100Mbps
Incredible Newsgroup Retention
1346 Days Binary Retention
3226 Days Text Retention
30 SSL Connections (256-bit)
Usenet Servers in N. America & Europe
24x7x365 Technical Support