New car audio for Octavia 2

Hello

I've been researching on the forums for a new car Audio as I have an 06 plate octavia 2 with a non mp3 stream

I like to listen to my music and podcasts in mp3 format.

I'm not fussed about sat nav.

I believe Bolero and columbus are two possible upgrades the stream mp3 seems hard to get hold of. I wasn't looking too spend to much around £100 max

I believe even if I went for a Bolero or columbus I would need to upgrade my CON bus? As they would drian my battery.

It also seems a lot of hassle & more expensive solution getting Bolero or Columbus if I won't use half the features. Is there any 1 or 2 din oem makes I could use without  the need to upgrade my CON bus?

Thanks in advance for any advice.