Would this make me a hypocrite?

Border collie puppies come through rescue all the time.  I think with your acreage and plans for agility, etc, you would be a great BC owner. 
 
I plan to get my girl ILP'd so we can compete in Rally soon (the only Rally around here is AKC).   Since BCs have such variety in color and shape, I dont imagine I would have a problem with the ILP.  Just fyi. 

No, that does not make you a hypocrite. As long as you have the dog's best interest at heart, you are not in the wrong.

I actually prefer rescue. I love puppies, don't get me wrong. I just prefer to skip the whole puppy and adolescent thing. That's my personal preference and other people have theirs as well. In a few years, I plan on getting another dog from a rescue. I don't know what breed I want, but it will probably be a purebred. I do like having a little bit of predictability, and I do not blame others for wanting the same thing.

Thank you all for your support and encouraging words.  I'm only in the early stages of "thinking" about what I want.  I still LOVE my "tzu-boys"; however, with my fostering resposibilites slowing down soon, my increased involvement with the Kennel Club events has peaked my interest in a more active dog to drag along once or twice/week! []  I just don't want to get in over my head and end up not being able to keep the dog's energy requirements satisfied.  Nor do I want to bring a dog into our home on a permanent basis (unlike the fosters) that cannot co-exist happily with my 2 tzus.[]

I'm still not 100% sure that I'll go the breeder route; who knows, I may run across a rescue that truly "fits the bill".  But the problem is that you usually don't know the dog's history and I won't know for sure how it will do with my dogs until I get in the middle of it, right?    I mean, they could be fine elsewhere, but maybe not so fine in our home together....  Wouldn't a puppy have more tendancy to adjust to small dogs and even cats better than an older dog - especially if it is a sporting or herding breed?

Also, should I be looking for a female since both tzus are male?[8|]

Now if you said you were going to get a dog from your next door neighbor whose bitch was great @ agility & got pregnant by mistake then I'd be all over you.

[sm=rotfl.gif]I would expect nothing less if that was my plan; and I would certainly hope SOMEONE would stop me![sm=flamethrower.gif]

I think you sound like most of us here.  You acknowledge that there's a pet overpopulation problem, but that there is also the place for a well bred purebreed. 
 
As far as getting a rescue dog vs breeder dog for agility.  I think it depends on what type/breed of dog you want.  I felt confident getting a rescue Malinois to do agility with.  BUT I just picked up my new basenji puppy from my breeder to do conformation/agility/coursing/therapy.  I'd get another rescue mal in a heartbeat to do performance, but probably will never get a rescue basenji for agility.  (Although, that being said, I did foster a basenji that had a good deal of potential for agility.  Since there are so few people doing agility with basenjis, however, I'd be reticent to take someone else's word on the potential of an individual basenji to do agility.)  I think there are enough lab's, bc's, goldens, shelties, etc in rescue that you could pick and choose and get a good agility dog from there.  Additionally you could probably find a rescue person who knows what makes a good agility/obedience prospect in these breeds. 
 
Now as far as the breeds you mentioned, I've seen several ESS's doing agility and while I have seen a few nice ones (dare we count the one at the Agility Invitational?), I think they tend to be incredibly difficult dogs to do agility with.  (keep in mind that I'm running basenjis.)
 
The latest unusual AKC breeds that have turned my head (agility-wise) that might fit your criteria would be the Pyrenean Shepherd. 
[linkhttp://www.akc.org/breeds/pyrenean_shepherd/index.cfm]http://www.akc.org/breeds/pyrenean_shepherd/index.cfm[/link]
The one at the Invitational was incredible in an event full of outstanding agility dogs.  Won his class.  Additionally there's one in my area that's doing a wonderful job in agility.  The European agility people have known about these dogs for years and they are just starting to be seen more in the US.
 
Tollers are also making a splash in the agility arena.  Nice dogs, but I've heard there are some problems with temperment in some lines. 
 
Feel free to pm me if you'd like to pick my brain some more on this.