Thank you for reply but I don't quite get it. Does it mean I don't get 100Mbps on the each interface of the HWIC-4ESW? Please elaborate on that.

You don't, beside the router also will have limited performances anyway.

You need an end ISR G2 to handle multiple fastehrenet at wire speed,

In fact that is what we are going for, either one 2901 with one HWIC-4ESW or 2911 with HWIC-2FE. Since the ISP dedicated links are 1, 2 o 4Mbps we don't need the full 100Mbps on each of the routers interfaces. 2901 with 4ESW will be the cheaper option but I would need to make sure if I can configure load-balancing, NAT/PAT , zone-based policy firewall or even redundant IPSec VPN on all the 3 VLANs.

Would that all be possible?

Thanks.

Yes. Keep in mind the best way to terminate circuit on a router is uning the native circuit interface, be that E1 or whatelse, and not any ethernet "converter", because that way you will be able monitor the true performance of the circuit, and apply QoS without complications.

Well that's not the case because the dedicated links are terminated on ISPs routers and we don't have access to them. So, VLANs on the HWIC-4ESW or native FE interfaces? Thanks