You can try:http://futoncoversforless.com/
This site has the best prices I have seen for the futon covers they carry:http://futoncoversforless.com/
This is such a personal preference thing.My futon cover came from:http://futoncoversforless.com/and I'm pleased with it's quality
You are best if you can live without carpet, but if you can't, vacuuming is you only alternative.I wrote an article about dust mite vaccums on my site:http://www.dustmites.org/dust-mite-treatments/vucuums-for-dust-mites
Opps, here is the dust mite site I created:http://www.dustmites.org/
If you want more info about dust mites and dust allergies, I created a web site about themwww.dustmites.org
You can buy a UV light here: http://www.allergyguarddirect.com/Dust-Mite-Treatment-Accessories/Verilux-Dust-Mite-Light-Wand-ll.aspI'm not sure its the best thing - here is an article I wrote about them:http://www.dustmites.org/dust-mite-treatments/uv-light-dust-mite-treatmentsI think you are better off with hardwood floors and quality covers.