For gearing, 10 speed is now all but standard on new MTB's from mid range up, with the introduction of 10 speed Deore for 2012, 9 speed was standard till 2010, when XT and SLX went 10 speed. 9 speed has been around since the late 90s, with 8 speed being long obsoletes since then, and parts supply in the UK is poor for anything except entry level components.

Lower end bikes will still have 7 / 8 speed, but due to the availbilty of parts, upgrading / replacing them can be harder than with 9/10 speed.

For lube types, have a look here http://www.finishlineusa.com/products/lubechoices.htm

For chain wear / lifetime, 1500 miles seems like a short distance for a chain, have you ever replaced your cassette? as these don't last forever, and a worn cassette can cause premature chain wear