I wear Pearl Izumi Tokyo Tights over cycling shorts but this is only in winter. But I would think they'd work for what you want to do. They're loose fitting and are more like pants rather than tights as the name implies. I got mine on sale thru Performance for $50.00 but this was quite a while ago. I can't even find them on Performance's website anymore. Here's a link to Pearl Izumi's listing for them...

http://www.pearlizumi.com/product.ph...&category_id=4

Keep in mind, these are not padded. They're made to wear over padded shorts or tights.