E53 Amp Upgrade Question

[BWilliams1216]

Alright experts, please help me out. I've spent the last 3 hours searching this sub-forum for an answer, no success (could be my density on the subject matter), so here goes.

I have a 2006 E53 X5, non-dsp, non navi, but with the HIFI 10 speaker set up and amp. Upgraded my factory speakers to the BSW kit because a couple of the stock midbass had blown. Overall I'm happy with the sound, much better than the factory setup. Come to find out no sound is coming from the right side midbass (new speaker). Figure an amp channel is blown and wanted to upgrade my amp anyhow, so I need suggestions.

I'm not interested in replacing it with another factory amp and I'm also not willing to wait for the BSW solution (seems like it has been in development for 3 or more years?), so what would everyone suggest to replace the stock amp?

I know next to nothing about audio and need some help, thanks in advance!