Advise on PSU and two GPU on MOBO

Hi guys.

My first post in these areas, as I've always let professionals do my hardware upgrades.

However, I've reached a point where I just want to be able to do "simple" things my self.

So currently I have an

- i5 2500K running at 4,3 cooled by an 

- Noctua NH-U9B SE2, and a 

- ASUS GeForce GTX 660Ti 2GB PhysX CUDA both on a 

- ASUS P8Z68-V LX, Socket-1155 motherboard, all powered by a

- (closing on 10 year old) Delta 750 W PSU.

I'm looking to install the Gigabyte GeForce G1 GTX 970 4GB (https://www.komplett.dk/gigabyte-geforce-g1-gaming-gtx-970-4gb/825299) to sit alongside the 660ti. I've been doing some messurements, and even though i'm not 100% sure, it should fit in my case (Cooler Master Elite 310). On the specs of the 970 G1, it says that the card requires 550W or greater PSU with a minimum 12V current rating of 42A. It's listed to consume 148W...

Here's a photo of the specs on the PSU, and it looks loke it's only rated to 18A at 12V (if i'm reading this correctly??).

http://i354.photobucket.com/albums/r417/mas618/Mobile%20Uploads/IMG_20150214_142548_zpsfeutvl5j.jpg

So my questions are:

1. Will the PSU on paper be able drive both cards?

2. Will it have the necessary headroom to drive both cards?

3. Would you advise to  upgrade the PSU on account of 2. or because it's getting old and could die any moment???

4. As the two cards are going to sit close to each other, would you recommend another 970 card with better cooling - I've read about the MSI card with the "twin Frozer" technology...??

Thanks for any suggestions and tips - anything will be much appreciated!

Mas