efibre Open Nats & Game Consoles

I'm with Eircom and I have there standard 24mb package although I only really get 10mb. I have a Netgear Modem/Router. There are a lot of games consoles and other devices running at once in my house and with my current setup they all have open Nats which is very necessary for me.

I want to switch to efibre for the speeds but not if it means I can't have open nats on everything. I have tried UPC broadband before and there speeds were great but it only allowed one open nat nad I had to contact them about it and they changed something in there modem settings to allow two open nats but they said it was not possible for anymore and you can only use there supplied modem router according to them. so I cancelled them. So I need to know a few things first before switching to efibre.

Can I use my own modem/router? (I understand I may need to buy a VDSl Modem Router I think it is for efibre) if so has anyone any recommendation?

Has anyone any experience with efibre and multiple open nats or even UPC?

I tried talking to eircom's customer support and asked them about a cooling off period after I purchased efibre if it did not meet my needs could I cancel and they were absolutely disgusting to me.

Any help would be greatly appreciated.