Here's the latest nightly build (605) http://bamboo.igniterealtime.org/artifact/SPARK-INSTALL4J/JOB1/build-605/Install 4j/spark_2_6_3_12555.exe
This build is on Java 7 and shouldn't have focus stealing issue (of course if you don't have Java 6 installed on the system, in that case Spark still uses system's Java 6). If you inspect this url, you can see where you can find newer builds as fixes are applied to the source.