I took my car to j b hi fi and got the kicker combo pack 4. It's a 4way channel amp and the basic comp sub 375 watts peak 175 rms. I also got a pair of kicker speakers as well.
All up $650 including sub amp install and side speakers install
It is very good for the price it is but if your a bass head I'd look for stronger amp, sub.
They said its not possible yet to take the head unit off.
But im thinking of upgrading to dual or maybe one 18".
My Bluetooth works fine.
You say you got the omega? Series 1 or II?
18,19 or 20 inch rims is the recommended size
18 is prob the best I reckon, I feel bumps on 18's so going up would kinda be worse.
You can check ozzytyres.com. They have a lot of custom rims plus they have Holden rims gallery.
Only thing is its online purchase, if you live close, lucky you. I think they still have that from 50% off rims and tyre package