I wasn't able to find the exact product in the photo but here are some similiar ones:

Twin bed on casters with trundle- http://www.ivgstores.com/IVG2/Y/ProductID-11767-.htm

Twin bed on wheels with trundle- http://www.amazon.com/Room-Magic-Trundle-Twin-Natural/dp/B0011FWVUA

Twin trundle- http://www.costco.com/Browse/Product.aspx?Prodid=10011816&search=trundle&Mo=31&cm_re=1_en-_-Top_Left_Nav-_-Top_search&lang=en-US&Nr=P_CatalogName:BC&Sp=S&N=5000043&whse=BC&Dx=mode+matchallpartial&Ntk=Text_Search&Dr=P_CatalogName:BC&Ne=4000000&D=trundle&Ntt=trundle&No=8&Ntx=mode+matchallpartial&Nty=1&topnav=&s=1

Same in blue- http://www.costco.com/Browse/Productgroup.aspx?Prodid=11307784&search=trundle&Mo=31&cm_re=1_en-_-Top_Left_Nav-_-Top_search&lang=en-US&Nr=P_CatalogName:BC&Sp=S&N=5000043&whse=BC&Dx=mode+matchallpartial&Ntk=Text_Search&Dr=P_CatalogName:BC&Ne=4000000&D=trundle&Ntt=trundle&No=2&Ntx=mode+matchallpartial&Nty=1&topnav=&s=1

Here is another trundle with plenty of storage- http://www.trundlebedstore.com/IVG2/N/ProductID-182708.htm

This trundle has a great style- http://www3.jcpenney.com/jcp/X6.aspx?GrpTyp=STY&ItemID=15a211c&RefPage=X6&deptID=0&catID=0&cmOrigID=1891d3e&cmPosID=1&CmCatId=searchresults

Here's another great bed with storage/display shelves (aka a "captain's bed")- http://www.kidsfurnituremart.com/kids-beds/bookcase-beds/littletreasuresbed.cfm

Hmm, a bed with wheels but no trundle- http://www.kidsfurnituremart.com/kids-beds/metal/teentrendsprimarytwinsizebed.cfm

Your other option is to buy a regular bed and add the wheels (or "casters") yourself or get a handyman/ handylady to do it for you- http://www.thisendup.com/parts/653/TrundleBedCasters.htm

Hope that helps! I'll let you know if I find the actual one.

- Rebecca

I liked the first one you sent from IVG. I just went for an iron bed for my daughter...maybe in couple years we change it again! Thanks for trying and send all these info!

This is a project by Alla Kazovsky. She designs/makes much of the furniture in her projects. I have a kid- friendly bookcase by her which is gorgeous and functional. Contact her directly and ask her.