New purchase advice

[Shadowsong]

Hi all, first post here and hoping to get some advice on a new router. I've combed through all the charts and reviews, but am still undecided as to what option would be best.

I currently have a Frizbox 7490 and the two main reasons i need to change it are that it cannot handle more then around 100mb down when any port forwarding is enabled and the second is that it only supports symmetrical NAT.

My main requirements are -

• I have currently have FTTP 330mb/50mb which will likely become 1Gbps in the future. I'd like to have a router that can handle that throughput even when i'm using port forwarding and so forth. (or as good as i can get)
• I host a website, teamspeak and few game servers so don't want to be stuck with symmetrical NAT where it constantly tries to map my specified port to a random external one.
• I would like the wifi to cover the 3 floors of my house with a decent level of signal. Faster the better really! (Current Fritzbox manages this so range shouldn't be an issue)
• Having more then 4 ports would be a bonus and link aggregation for my NAS would be even better. But neither is essential.

I've no real budget for this as I plan on getting which ever best fit's what i need it to do! Originally I had planned to get the ASUS RT-AC88U but it seems that it's being discontinued now, which is what lead me here.

Any suggestions would be appreciated!