I'm using a 20gb IDE SSD in my AmigaOne, it's faster than the IDE HDD I took out, it was about £35 and made by Kingspec and I've been running it for about a year now, it works great & seems to be reliable. My A1 hasn't had heavy use although it did a full weekend at Amimeet earlier in the year!
Here's a similar one on eBay:
http://www.ebay.co.uk/itm/KingSpec-2...item4605d162a9