Z906 durability is random. Only a select few will have a volume pod problem that makes low volume and cannot control.
Overall its a good system for startup I'd say. Comes with Dolby and THX approved with various inputs for home tv use.
I don't know what input you can support with your pc. Optical? HDMI? Analog 5.1?

What are your budget range?

idk why you don't want a 2.1 system but

why not explore Edifier lineups?
especially the Edifier S760D. Easily defeats the Z906 with power and clarity anytime.

If you want a slightly budget range, the Edifier C6XD is quite all in one for minimal price.
If you are ok with messy analog wires, you can opt for a slightly budget version of S760D which is the S550 Encore.
Or a smaller system which is the R501TIII

Definitely can't defeat the logitech Z906 if you compare C6XD there. Overall I'd think the top end is fine but the subwoofer is going to be missing out a lot.
But if you said analog connections are okay then the R501TIII or DA5100 will be a fair comparison to Z906. At least that has a more full overall sound.

Alternatively you can opt for a standalone av receiver to connect your existing pioneer setup. At least can make full use of your old speaker instead of buying more speakers if you still have em.
Denon AVR-X250BT would be around your RM1.2k budget with both analog and digital/HDMI connection for bypass.
Definitely not a space saver setup though 

I just discussed this few post behind. You'll need a form of volume control to be your master volume to control both your speaker and subwoofer.
Yeah there are drawbacks like losing extra functions like bluetooth or wireless volume remote since there is no dedicated sub out but that shouldn't stop you from adding subwoofer in the future.

I can say Edifier T5 is the most affordable subwoofer I know of so far. :thumbsup:

its hard to find edifier s350db in northern region...i dont think there is shop got sell...have to travel all the way to kl to buy it...For speakers, i dont dare to purchase online...i am afraid that the logistic throw the packaging and spoil the speakers.

Which online shops do you recommend for AV gear such as speakers, amps, receivers, etc?

SLT seems to be based in Singapore?

I don't have much experience in RM2k pricing but may I know if these is for TV or PC use?

if TV I had a wishlist of buying Sony SS-CS3 towers for my home use paired with my very underpowered NAD302 amp. (Can be substituted with a proper powered amp but idk what to use other than chinese amps)
Edifier S2000MKII is quite highly recommended so far if you don't mind buying Edifiers again. Not as muddy as R1700DB Not analytical but fun to hear tuning.