if you don't want to order unless in stock you can use www.eyeitforme.com to monitor the availability (ASIN is found on product page, for the SSD it's B002IJA1EG)
if i were you i'd just order it though, amazon has a record for randomly stocking items, i waited forever to order my hd5770 since it said "out of stock" for like 3 weeks, i used eyeitforme and i figured out they were restocking and selling out before i checked it again