I have very minimal experience with SMAW on aluminum, but the best welding aluminum stick electrode I ever tried was manufactured by Rockmount / Nassau.  Whatever you use, be sure you meet the required storage requirements.  Alum rod left out deteriorates pretty bad, doesn't weld well, and is prone to porosity.

That said SMAW on aluminum can still be a struggle.  If you have to use SMAW and have a DC power souce that will take a remote, a foot pedal or remote amperage device will improve matters.  Just like with TIG you need more heat to start, less once underway, and little towards the end of a joint.  If you have a remote device and are well coordinated you can turn it down with one hand while underway, or have a helper turn it down on command. 

And of course using techniques to control the extent of  base metal and electrode temperature changes will help, such as only welding a few inches, welding from the ends of a joint towards the center, controlling preheat and interpass temp, stopping before the electrode burns down far enough to get excessively hot and starts falling off, using run off tabs, etc.

I'd recommend you think about braze welding instead of SMAW. Tensile/Yield of brazing material often meets or exceeds that of the base materal, depending on what the base is and the selected filler is. Silicon Bronze could be expected to give good results on aluminum. SMAW not generally considered for high quality welds, GMAW or GTAW are usually the processes of choice when high quality welds must be made in aluminum. In addition a lot of cast aluminum is not considered to be weldable: for example 2000 series alloys are usually considered non weldable and most 7000 series castings are not considered good candidates for welding.