I have a flight BHX - KUL in J coming up and about 50000 miles about to expire. Rather than buying some crap from Emirates High Street was wondering if it was worth the upgrade to F. BHX - DXB only has J and Y but could upgrade one of the DXB - KUL legs.

EK 408 (Suites) on 06/04/12 is not showing any availability for upgrades on emirates site (I don't have access to expert flyer) but EK 343 (Skycruiser) on 15/04/12 is.
Is it worth using the miles for the non suites product? Are seats likely to be available nearer the time on 408. I am currently only Silver if it makes any difference. Thanks.