I'd like to get some thoughts installing routers (and recommendations if possible)

We are a small company (20 users) and are preparing to install a Mitel 3300 phone system.
Half way into the planning process, the phone vendor informed me that our T1 access router needs to support QoS and priority tagging, and an additional DMZ port to support teleworkers. Currently, ours does not and is provided by our carrier. If at all possible, we want to preserve this existing router as it is managed by the provider and they do not provide one with these features.

Phone lines will come in over a PRI to the mitel and out over a vlan to user desk sets.
Both Voice and NetData are seperated on their own VLAN.

We will also have 3 teleworkers that we are connecting to the system. To do this, we need a router that supports QoS and has 2 available Ethernet ports. One port that will connect to a firewall providing internet access, and one DMZ connecting to the Mitel CX controller to handle voice between our location and teleworkers over IP.

My question is, can we put an additional router in between the T1 access router and the firewall that will support these requirements (QoS, DMZ)?
Will QoS tagged packets be passed through the T1 access router if it does not do QoS itself?

I have been quoted for a Cisco 1841 Integrated Services router @ $2,200.00 but I have also seen other products at half that cost or less (HP ProCurve 7102dl Router, Kentrox Q2300 Access Router). Are these, or others ( recommendations please), capable of doing the same job without the Cisco Price Tag??

Can an Access Router be used without using the WAN (T1 or DSL) interface but only routing features for private network??

I would be concerned about a vendor that informs you of this during the project. This should have all been determined up front. This could lead to huge cost overruns.

If your present T1 router isn't passing or QoS capable you can't use it in this configuration. Period.

This means a new router. Do you presently have a switch which supports VLans?

Are you seriously planning on VoIP phones for your telecommuters? You do understand that this means VoIP phones and routers at their homes, right?

If you are NOT considering VoIP phones for the telecommuters then all you need is a router capable of VPN's which will allow them to connect via the web into work. I see no mention of vpns which is a serious lack of planning mistake.

I would not be a happy camper if I were you.

Golly gee wilerkers everyone! Learn to Internet Search

I am fully aware of the router requirements on the remote side. The system is a Mitel 3300 with CX controller and Teleworker Solution using IP phones. The Mitel will be configured to operate over a vlan. Switches are ProCurve 2626 PoE. The 3300 and Teleworker Solution manage all phone connections and the VPN issues.

Your response still does not answer any of my questions.

"My question is, can we put an additional router in between the T1 access router "
Answered: no

"Will QoS tagged packets be passed through the T1 access router if it does not do QoS itself?"
Answered: no

"Can an Access Router be used without using the WAN (T1 or DSL) interface but only routing features for private network??"

Answer: can't say. It depends on a number of things. Start you informational dig here
http://www.cisco.com/en/US/products/hw/routers/ps221/

I have worked with other routers but Cisco is worth the money for routers [not switches though]

Golly gee wilerkers everyone. Learn to Internet Search

The teleworker solution is a firewall in its own right (linux) and can sit on the raw side of your firewall. You dont have to put it on the DMZ - its just better if you can.