I quite liked the Vax Air cylinder - it had very strong suction, wasn't too loud and because it didn't have a shroud, it was easier to empty than a Dyson cylinder as the dust didn't get stuck in big lumps in the bin.
[URL unfurl="true"]http://www.amazon.co.uk/Vax-C89-MA-B-Multicyclonic-Bagless-Cylinder/dp/B004ZJMF00[/URL]