G'day Chippy,
My kids all have swags for the same reason you have stated above, my eldest daughter has a Burke and Wills Swag, and it's pretty good for the dollars... Though in saying that, if you are going to be using the swags inside tents etc, and aren't really after a full blown sleep under the stars in any weather type swag, maybe you should just be heading down to your local canvas man and getting some "lite duty" canvas bed rolls made up, then go to the rubber shop and price some "true" high density 2" thick foam rubber, the comfort you'll get from a high quality foam matress is worth every cent.... i replaced all the so called factory high density matresses in our swags with foam bought from a local rubber shop, i think a sheet of foam cost about $280 and i made up 3 or 4 matresses from the sheet, now our swags are very comfortable....
Like i said though, if your sleeping under cover, don't get too hung up on the canvas quality, just get swags that fit the kids for now and a few years to come, and spend the extra bucks on quality foam rubber, chances are the kids will sleep on the swag in a sleeping bag, so won't even pull the canvas over themselves..... thats my opinion anyway.
anyway here's some info on the burke and wills,
http://www.ebay.com.au/itm/Burke-and-Wills-Rivergum-Traditional-Canvas-Swag-/370516902163?pt=AU_Tents&hash=item5644874113