For that about the lightest and most compact are ZZZing Rollers. They aren't made any longer but you can probably find some. Here's an old eBay listing:http://www.ebay.com/itm/ZZZing-Rollers- ... 7675.l2557
This just gives you an idea of what they're like; unfortunately no photos available.
I think the guy who made them is
Lewisberry, US 17339
Not sure, but call him and see. If he's the guy, he at least may know where there are some for sale. They are good quality (all-alloy drums, nice machined alloy rails, just made very light and so they come apart and pack in a smallish bag). If you can't find those, I'd suggest you just think about some Kreitler Kompacts, and possibly get the Hot Dog version (only 10 inches wide) if you want to save a lot of space (but not much difference in weight). The Kompacts have a simpler and better mounting for the drums. They don't slide back and forth for quick-release adjustment for wheelbase (since it's your bike and your rollers, you probably keep them in the same place anyway, and the quick-release adjustment always slips when you fold them up and pack them). You can take either the Hot Dogs or the wider ones and spin on or off the acorn nuts on the ends in a couple minutes and pack the three drums in some homemade neoprene tubes to protect them. If you want to save more weight, you can get a machine shop to make the rails in alloy for you -- it's trivial welding and then just powdercoat them for about $30. You can get Hot Dogs down to under 20 pounds that way. You are stuck with the length of the rails (they fold in half but it's still about 3 feet long) but everything else is pretty compact. Personally if I was really trying to make this work I'd go the route of the Hot Dog Kompacts, have some alloy rails fabricated, and pack a box-end wrench with the rollers for quick assembly and disassembly. And definitely protect the drums with sleeves made from wet-suit Neoprene.
I've raced track all over the world and traveled with hundreds of track cyclists and watched probably thousands at track events, and we all live on rollers or trainers. None of us have ever had any light or compact solutions better than what I've described above. Sorry about that.