Which RB ver is suitable ?

Hi,

I am running network with around 300 users.
I want to setup PPPoE along with user manager on MT RB.
Network is totally wired. NO wireless.

Which RB ver is suitable for my network ?
Which License Level will fulfill my requirements?

So you will have 300 PPPoE tunnels? RouterOS level5 allows 500 PPPoE tunnels. http://www.mikrotik.com/pricelist.php

Which routerboard you’ll need depends on how much traffic will be flowing through the network and if you are going to use queues, etc… You’ll probably need a RB1000 or a PC running RouterOS

Probably RB433AH could work too

Max. Active pppoe connection will be around 200+
there will be various queues for difference clients.
& most importantly good PROXY CACHE is required.

In routerOS I can add secodary HDD, but how can I get extra space (around 40GB) for CACHE in routerboard ?

RB1000 has CF slots. You can buy 32Gb CF cards for cheap prices on ebay