Green Drive vs a RE4-GP

I'm looking to setup a RAID 1 with two 2TB WD drives, or a 0+1 and four 1TB drives.

First; I've head a lot of people having problems with a drive falling out of the RAID or not being recognized, is this because of cheaper RAID cards or the drives or just the nature of the beast?

Second; I'd like to keep the power usage as low as possible and have thought about the WD Green line of drives but I'd rather fork out the extra $$$ for the RE drives if it will help keep the RAID healthy, any recommendation?

Third and lastly; I would like to go with a PCIe RAID card but can't justify spending $100-$200-$300. So I might be limited to just a PCI RAID card, any recommendations on a good mid level 2-4 SATA port card? Will not be booting from card.

To fill in the gaps; I will be use it for a WHS but I'm not planing on streaming video at this point but it would be nice if the price of the card vs options is right. I also love the resources of newegg and links would be awesome as I will be buying from newegg.

Thanks everyone!!!

1. WD has changed the "tler" settings (google has a lot of returns on WDD+tler) on its HDDs several months ago. Non RE HDDs are likely to lose their RAID volumes; the volumes be re-built, but it becomes annoying. AFAIK WD doesn't have any green REs. It sounds like you should be using the REs for your system.

2. RAID add-in cards: I don't know enough about them to help you.

Thanks, I'll look to get the RE drives when I get to that step. Have to take it step by step as I don't have $600-$800 to fork out at once.

I've heard someone talking about the ZFS file system, I'll have to check into it and do some reading, thanks.

Frankly, I was hopping to have heard from someone in regards to a good but cheaper RAID card, as that's the next item on the list to decide on.

Anyone, Anyone?