Allright its time to get rid of my sub-par stock system.

I have a 99 CL.

Head Unit im planning on a Alpine 9835. Have to buy one off of Ebay.
Would it be wise to power this directly from the battery, or will it be fine as is if im going to run amps? Also, what kit should I buy to put in the new HU? Can I keep the box under the HU?

Speakers - I have a pair of Infinity Kappa 6x9s that have been laying around for a while for the rears.
For the fronts I was thinking of some Kappa 60.5cs component speakers. I had some in my integra and the only real complaint I had was that the sound was a little bright, which could be fixed by turning the treble down.
How hard is it to replace the stock tweeters in their current location and will I have a problem getting some 6.5'' speakers in the doors or will i have to modify the depth?

For a sub im not really into huge bass but like to keep it clean and I also like to haul stuff in my trunk. I had a Kicker substation in my integra also and was just thinking about buying another one cause it worked well.

Planning on buying an alpine amp or two, should I buy a 5 channel amp like a mrv-f450 or get one for speakers and a seperate one for sub?

One more question, I wanted to do XM, how hard is it to install the antenna correctly?

Thanks a lot, I know this is a lot at once but I want to do it right.