Yes, definitely will get a battery back-up with it.
The controller you've got, it seems used? I'm not sure if i want to get a used one... maybe something can be wrong with it, or may only have 1/2 of its life left? What's your opinion on that?
With regards to memory chip, would i get a better performance if i get 1Gb cache chip on the p410? Like this one: http://www.ebay.com/itm/HP-P410-1GB-Flash-Back-Cache-Controller-572532-B21-/161072841831?pt=US_Server_Disk_Controllers_RAID_Cards&hash=item2580b08467
I think i already have the 2 cables that are currently connected to my P400, so probably don't need the cables.
Thanks