My seicento ICE, Advice plz?

Hey,
Just got a little seicento for my 1st car (1.1 Seicento S 2001)
I need some advice on what ice to have installed...
i was thinking about
sony xplod 444 amp
sony or kicker 200watt sub
2 100 watt infinity 6x9
And keep the stock head unit (Sony XR-C5300R) [4x50watt]

Or should I
have the front two speakers upgraded
444 xplod amp
400 watt sub

Thanks
Ryan

Any other suggestions welcome

sony xplod is crap stuff lol you want to go for a sub with a high RMS output not peak dual voice coil is a good idea. a good quality amp aswell. i would stick with things like kenwwod, kicker or like i have got pyle audio which is a very good cheapish brand but my equipment is amazing and sounds great

okay mate, i will research my stuff, however which option do you think will be best? I wont need to get a new head unit to get new front speakers or anything will i? thats all im worried about, because i know what im doing amp&sub-wise
thanks
ryan

How much you got to spend?

erm... i've got about 150 quid for all of it.