@Mukilan_ Take your time to learn the basics of speaker related terminology and then think about DIY. DIY is expensive if you are a total noob. You must pick up one of these skills to save on cost:
Building a crossover network (electronics)
Building speaker boxes or baffles (carpentry)
I would suggest that you experience a proper stereo setup (used ones) for a few months before actually thinking about DIY. DIY is for brave hearts.
Every ordinary stereo setup would still be a wow compared to IEM world as the 3D imaging felt outside your ear canals will be a significantly different experience.
But, if you are confident about your DIY abilities, then here are my suggestions without any budgets mentioned:
If you have space to place speakers away from the wall, then check the forum on Ahuja open baffles. Diy audio has Manzanita which is a super simple project to execute.
Philips HIQ speakers can be done in both open baffles as well as simple bass reflex (ported speakers).
Please feel free to post what amplifier you have as of now and what is your overall budget?