As i have read until now (monstly through cisco books, CCNA and CCNP) those prodocols are those that are suggested for using in your network. I use EIGRP in my network since all my devices are Cisco(also the switches). My network has now around 50 nodes and in 1-2 years for now it will reach the 100. Since OSPF has the areas which i don't know if i can do that with EIGRP what do you suggest about my network.
1. Do you suggest to use OSPF since my network is increasing and use areas?
2. Can i do that with EIGRP in a similar way, for examble differnt Autonomous System number?
3. In one area or AS what's the max number of nodes we should have ?
Since these are two different types of protocols, the way they scale, and their scaling properties, are completely different. With OSPF, you need flooding domain boundaries to cut down on the information in the database, and to provide places where you can aggregate. With EIGRP, topology aggregation occurs at every hop, and route aggregation may be configured anyplace, so there's no need for flooding domain boundaries.
We see EIGRP networks, in a single AS, with up to 2000 routers, so you're nowhere near any sort of "router count limit" for EIGRP. In fact, IMHO, all the ideas of how large a network should get before you "switch protocols" ignore one basic point--scaling is dependent on design, not on the protocol itself.
You choose a routing protocol because of properties involving your business needs and how well the protocol meshes with your network design and maintenance practices, not because one will scale or converge faster than some other protocol.