If only been used for games stick with the 1200 with no accelarator.
If you want to use the more highspec games go for the 4000 as it is easy to buy and install yourself the upgrades.
For ethernetcards go for the mediator in a A4000 the busboards are "low" priced these days and nothing beats the voodoo card in the mediator(which you could find second-hand).
Ethernet card for the mediator is even easier to find and cheap!
For games in the 4000 dont go any further then a 030.
Even with WHD-load the 040 often causes problems.
