Replacing a C42 with a R990

Hi All

This is only my second posting, although I must admit to using this forum a lot to acquire information -thanks . I have recently purchased a low mileage TD5 GS, I was wanting an ES spec but could not find a good one in my bracket. Any way this leads me to my question, and up front may I apologise if i am rehashing old ground, but after a lot of fruitless searches, I have decided to ask -
I would like to replace my standard headunit (C42 phillips) with the R990 (Alpine) unit as found in the ES. I realise that this unit is amped -
am I correct that the amp is XQK 000010?
I am also aware that my speakers, 6 in all are rated 15W whereas the ES contains 12 speakers rated 30W.
Can anyone assist me as to understand if this upgrade is possible and what I would need?
I do currently have the steering volume controls fitted.
Many thanks in advance ,

I recently bought an iso harness off of ebay only to find that the Headunit i got from halfrauds came with one so i have one spare if you need it.
Apart from that i dont know much yet as i am also new to land rovers.
I am getting some new speakers soon though, they look a lot easier to fit than my mondeo was.

Hi Symun

Thanks for your quick response and harness offer (I take it that this is one for the hi line ,alpine system?). I am still trying to gauge what I may need to do this replacement, thus my posting. Let me know what you want for the harness and if I need to go that route I can contact you.
Thanks!