stereo upgrade, help!

[aml]

hi, i am wanting to upgrade my stereo in my 2003 mini one

i am looking for:

direct replacement front component speakers - what size are the standard speakers?
6x9 rear speakers (looking at the genesis 6x9 subs)
4 channel amplifier to drive all speakers - needs to be hidden, i am investigating if a Sony XM-4S (223x196x43.5mm) will fit where the harmon kardan amp goes, or is there a possability an amp could go under the rear seats??

although, i want to keep my standard cd radio mini head unit and just add an ipod inteface, as i want to keep the standard look, can an amp be connected to the standard head unit??

suggestions and answers will be greatly appreciated, cheers

[GBMINI]

For front speakers, you're best to get adaptor rings and fit 6.5" speakers - larger=better
You should visit NewMINIstuff for lots of parts ideas / etc - they have amps that can be hidden (and you need speaker level inputs on the amp, or line level converters, to use the stock HU)

[aml]

i have narrowed down to:
Blaupunkt tha 475 600w 4 channel amp (under front seat) £170 - looks fantastic!! (can somebody please confirm that this would be compatable with the standard head unit?)
genesis 6x9 rear speakers £170
JBL gto606c 6.5" front components £60

also, will the newministuff adaptor plates fit behind the stock mini speaker grills?

[aml]

the amplifier i would like to use is 2ohm, but all speakers i would like to use are 4ohm, are they compatable with the amp?? cheers

[GBMINI]

Yes.
2 ohms is a minimum - 4 is more so fine.
If the amp was 4 and the speakers 2, then you'd have trouble