Upgrading Home Network

Good Day Everybody!

I am looking to buy a new up to the minute PC and make the most of the cheap
prices in the UK. I want to try to use my old PC ( a 3 1/2 year old 3.GHz
Pentium 4 with 300GB HDDs (150GB SATA) and 1GB Ram) as a server because I
can!

Networked to this (wireless) will be my new PC - spec to be decided, and my
laptop (1.GHz Celeron Mobile thingy with 500Mb Ram and 80GB HDD), via a
Netgear router modem.

The new PC will be used mainly for everyday work, not gaming, internet
obviously, and downloading! I will be making a lot of DVDs from AVI files on
the PC, and want to use the laptop for more casual browsing and office work.
I mainly want the old PC to be used as data storage and a focal point for my
printers (Epson DX5000 & HP Laserjet 1010). Also connected to it will be my
external HDD (300Gb x2 - Seagate).

The laptop will need to be used also as a stand alone unit when I go away on
business - taking with me the external HDDs.

I consider myself fairly proficient with XP, but have yet to use Vista in
anger! Both the old PC and laptop require reinstalling of windows - as they
have not been done in such a long time and are struggling along, and am
quite happy with doing this.

What I would like some advice on is - what versions of XP or Vista should I
use on what machine to make the best use of what I want - I need to access
email from either the new PC or laptop ( i know I can use webmail but I do
like Outlook!), and that I can use the laptop when away from home, still
having full access to the laptop HDD and the ext HDD! (When I am away I use
the laptop mainly for entertainment!).

Hope this makes sense and its not too long winded.

Your thoughts are appreciated, and many thanks in advance

Matt