Upgrading Speakers Only - Yamaha YHT 299

[zzzeharzzzehar]

Hello Friends, just found out about this amazing forum! I am in a bit of a dilemma and need advice.

I currently have a Yamaha YHT 299 5.1 Home Theater in a Box package, it comes with NS-B20 fronts and surround speakers and NS-C20 center channel. The subwoofer is NS-SW20. The AVR is HTR-3066 that came along with the package.

I am looking to upgrade the speakers and subwoofer and inclined to buy used. My budget is max of Rs 35000 (+/-10%). I am okay with keeping my existing sub for sometime and upgrade gradually if I cannot manage it within the current budget but I'd prefer to get fronts and center channel and if not lastly, just the fronts for now and upgrade center and sub later. I have shortlisted the following options; I am leaning towards floor standing speakers but would love options on bookshelf speakers that are significantly better than these floor standing speakers.

1. Taga Harmony TAV 507 5.0
2. Mission M74 - just the front pair
3. Denon SC-A55XG bookshelf

I am looking to get the max bang for buck but most importantly, a significant upgrade over my current system. I am okay with selling my entire YHT 299 and upgrading the whole things as well if I can manage within the increased budget. Pls suggest! I will continue using the same AVR for now i.e. HTR 3066.