If you are looking for a Kevlar liner, Draggin jeans makes one. But they cost more than a nice pair of riding jeans.
http://www.dragginjeans.com/mens/draggin-liners/
Hood jeans is closing out their current line of jeans to meet the new European spec. So they are selling it for 20% off. I have heard great things about them.
http://www.hoodjeans.co.uk/
When I don't wear my main riding pants, I currently ride with either some Slider Kevlar jeans or Aerostich Cordura lined jeans. Neither are great compared to my regular riding pants (Motoport Kevlar mesh over pants), but they work when I have to go to a design meeting and want to ride. I do like the removable armor in the knees on the Aerostich pants, it has zippers on the outside, so you can pull the armor when not riding. I am tempted to pick up a pair of Hood jeans to see how they compare.
Are far as boots. If you like Vans, Bates makes some riding shoes that are on close out at Iron Pony for not much more than a pair of Vans. I ordered a pair to see how I like them.
https://www.ironpony.com/ipd/pl.asp/...treet-Products
Get a heavier jacket for the fall and winter. I have read good things about Fox Creek Leathers and have seen them go for downright cheap money on Ebay.