As you mentioned you are going for Hyundai Eon Era Plus LPG, which comes with factory fitted LPG kit, therefore there are no chances that your engine can fail in just 4-5 years. Today the LPG kits are more advance and companies use the best kit for their cars therefore you get better fuel economy and engine life than an aftermarket LPG kit.
There are many options available for a 2 DIN music system for Hyundai EON in the market. You can check with a local car accessory shop to know about the options in detail. Also, you can check out some options on our online shopping portal. Please find a link below to check out the music systems http://shop.cardekho.com/car-accessories/music-systems.html