How to merge 2 LANs in 1 LAN withw 2 Gateways?

[conx]

Hello,
I have two LANs. The first has 3 computers and router. The second has 2 computers and router. Every LAN has Internet connection 2 MB each. I want to merge the 2 LANs so I can get two gateways in one LAN. If one gateway broke down the other one will work. and If the first connection's bandwidth consumed the other will work. Please, explain in details. I'm newbie.
Sorry for my bad English.

 

[lyleb]

You would need a dual WAN router. There are still some around.
Or you could use DD-WRT or OPENWRT on a supported router.

 

[conx]

Thanks lyleb for reply.
But If I used a dual WAN router or OPENWRT. Will I have 2 gateways?