I've started a Strathclyde Welsh warband for Saga. They are all horse and javelins. I used the Gripping Beast Plastic Dark Age Cavalry set. But, I'm thinking I can get some use out of them with my 12th Century English army in Sword and Spear, so I ditched the Roman style helmets, and gave them a few more Norman style ones. I also added some cloaks from the Fireforge crusader boxes.
I quite liked the Dark Age Cavalry box, but the horse halves are not interchangeable, so you don't get that variety of poses. I am very pleased with the variety of poses you get with the riders, though. Also, I think the cloaks add a bit of dynamism that they were lacking.