I think the rods are like $10-20 ea. 8" thru 22" if I remember correctly. I believe the aluminum rods are stronger, they're like 10 times thicker.
A very good source of info for people like you and I who like to make/mod stuff ourselves is Circle Track Magazine. They have great articles on all kinds of stuff, but look at the ads and order catalogs from these places. There are several rod end mfgs and they will send free catalogs, but look at everything like A&A mfg, Jaz products, etc. If they say send $5 for a catalog in the ad, then phone in the order. Only once was I ever asked to pay.
Distributors like the following are great sources:
http://store.summitracing.com
http://www.speedwaymotors.com
http://www.portcityracing.com
Port City’s catalog is a must have item for you.