How would these work. They are steel so too heavy? Here they are - they are steel. J for front, K for rear? Prices in Cdn$.

To be honest the 'J' for the fronts would IMHO look nasty!!

You may get away with 'K' for the rears but as you say, "Too heavy" so i would stick with plastic ones.

Another 2p spent!

On a point of pedantry, I would think the difference in weight would be marginal. The steel items probably being made from 18 gauge and the GRP probably being about 3-4mm thick.
Opinion based on the weight of the bonnet of a Scimitar I used to own.
On the looks front there's no competition, GRP all the way.

Mick

these aluminium ones look better to me (but expensive)
http://www.richies.us/products.htm

http://www.trailerpartswarehouse.co.uk/trailer_mudguards/single_steel_mudguards.html
worth a try