As someone who used to run a pick and place workshop i would recommend this
http://uk.farnell.com/multicore-loctite/96scrp15ags84-25g/solder-paste-96scrp15ags84-25g/dp/1115454

I have removed surface mount processors and replaced them with little more that this stuff a good clean soldering iron and a magnifying glass.(and some solder braid- just incase!)

I have stopped using RS online as it never finds stuff that you know for a fact they supply!