This is in an HP Envy with a z87 chipset, correct? Does it have a K series processor (unlocked CPU multiplier)? That is the only way to achieve a noticeable overclock with z87. You will need that before starting to search for a replacement BIOS that has multiplier adjustments.
Personally I would stick with what you have until you need an upgrade, then look into a custom built system with the proper CPU, CPU cooling, motherboard and power supply needed for a reliable overclock.