What is the diameter of the objective? If it's fairly small 1000 mm might be ok. It really depends on how much abberation you can take and still be satisfied with it. Also, you will have zoom with any setup, otherwise it's not working correctly.
A quick google search for "building a telescope" revealed multiple sites that seem to be good. Here's a link to one.
Also, you might be able to find some objectives and various other parts at this site for a good price: http://www.surplusshed.com/new.html