SATA setup

Am expecting delivery tomorrow of new processor and HD's (already purchased Mobo) so need a bit of guidance to set new rig. The new rig ...
ABIT AN8 / AMD ATHLON X2 4200 / 2 Western Digital SATA 250 Gig...
Present setup is 2 Western Digital 125 Gig Striped 0, what I want to do is Stripe the 2/250's WD the same and then have the other 2 WD 125's (existing HD's) striped as Slave..
Will BIOS tell me that after initial Stripe(Master) has been setup with OS that the other 2/125's will automatically become slaved. Now to get to the nitty gritty I need to set it all up so as I can then clone the 125's to the 250's if that is at all possible. Have been looking all over the net but cannot find any info on this specific setup.. Hope this is clearer than my head lol

 

Well delivery is late so can post another quest.. after I have Striped the new HD's and setup the OS I will then connect the old HD's, now seeing they have a striped array from me old Mobo will they be recognised and reachable without ruining the stripe as I know from past experience that all data will then be lost, if that is possible should I be able to drag data accross even if I cannot Ghost them... ???