I personally use a few plugins, mostly synthesisizers, but from experience, sometimes all you need is one synth and you're good to go. Synthesisers: Sylenth1 - I love it loads and it's very powerful. read more
AND: before I end this, I highly recommend you to go and explore Splice Sounds - they have samples for multiple genres of music that you can use for the price of $9.99/month. I use it all the time to find samples for new songs. read more
Even if you do get Logic, to make high quality house music, you will absolutely want to buy some extra virtual instruments. Logic Pro X comes with Alchemy which is an amazingly powerful synth and Sculpture which isn’t a synth I commonly use but it is unique and good for making more realistic sounding instruments. read more