Hi Sasi,
Please find my responses inline:
1) What type of scenario will be going to use. (The Both ISP link will be available)
2) The Inbound and outbound traffic will be coming and going via both link using my IP Pool.
response to 1 and 2
[Sarab] : It depends how to advertise you subnets to ISP. Because it is them who would influence inbound traffic.
One way would be to advertise half os subnet via one and other half through other ISP. Though this wont ensure equal utilisation however it will keep both links occupied depening on the traffic sent for the subnets advertised to these ISP.
For outbound traffic, since you will be employing NAT, you can try doing Policy based routing to push traffic based on certain conditions like source/destination prefix or port to desired ISP.
3) Where can i NAT my 255 IPaddresses for my internal servers
[Sarab] : You have to NAT them on the outgoing interfaces only depending on which ISP you are advertising prefix to.
5) What type of protocol will be going to use.
[Sarab] : For such cases BGP is best suited as you have your public subnet as well as AS number.