I can't imagine any advantage of using that type of seedling cells for pecans, and the small number you are growing makes it even more confusing to me. If you are set on doing it for some reason, go with the largest ones. The root system of a pecan will develop significantly before you get much top growth. You will need to plan to transplanting (and fixing/properly pruning the root system) very soon. Hopefully you already know that simply potting up a deformed root system will very likely lead to an early demise of your trees (and possibly stunted growth from an early age).

Have you thought about planting your tree seeds (especially the pecans) out directly where you want the tree? With proper protection from predation and a decent climate, you'd probably be better off. For the first year or maybe even two, you might have to water them in times of drought. But, if planted from seed, the trees' root systems would be completely established and well adapted to conditions at their planting location. Alternately, I'd use small, but tall, nursery pots and plan on properly root pruning at transplant.

yakin,
I've grown thousands of seedling pecans - some for use as rootstock for grafted pecan & hickory, some for outplanting for wildlife. Direct-seeding is a good idea, if that'll work for you.

Cold, moist stratification is not necessarily required for pecans. I just store mine, dry, in a cool dry place(the barn), then soak them for 4-5 days prior to planting in the spring.
I'd opt for the Treepots - and the 14-16" are best - but I have grown oak & pecan seedlings in 1/2 gallon milk/OJ cartons (essentially that's what a Whitcomb pot is) with the bottoms cut out, on a raised hardware cloth platform, so that when the taproot exits the growth medium, it is air-pruned and begins to develop a more lateralized root system

Here is a link that might be useful: Containerized growing of oak/nut trees for outplanting

Womack Nursery will sell you seedling pecans next winter if your pecan seeds don't generate.

As for bald cypress, you have several rivers in the area that are lined with native bald cypress. I have collected seeds before from the Medina, Sabinal, Frio, and Guadalupe Rivers. Its a bit late, but you should be able to find some seeds if you start looking as soon as possible.

I simply let mine dry for about a month then bag them and put in the frig. About first week in January plant about 50 seeds to a 5 gallon pot. The pot remains in a tub of water from Jan to mid-May, at which point I pull it out and set it in the sun, watering about every other day. Ususally have way too many seed germinate. Late in summmer/early fall the seedlings are separated into their own 5 gal pots and grown another year before transplanting.
You will need to provide additional water for about 2 years to get them established.

You might also consider planting just a few grafted trees, also, if you think you'd enjoy some pecans for yourself. Nolin River Nut Tree Nursery is another good option for grafted trees.

Thanks for all the replies!

I really didn't know which cells/planters to use...I'm very new to trees/plants in general, and I thought it sounded like an interesting project. I have a number of large pecan trees on my small farm, and a few of these are larger nut grafted variety. A couple of my smaller, recently planted pecans are grafted trees as well. I'm mainly looking for a cheap way to line the waterways at my wife's ranch with beneficial trees, so I thought cultivating my own cypress and pecan trees might be amusing.

I will most likely directly seed a few dozen pecans, and try to go find some cypress trees using scotjute's method.

I will also try the milk/orange juice container method...air pruned roots are what I had read about and sounded like a great way to get a seedling started. Great read lucky, thank you!

brandon, I order my American persimmons from Nolin, great company.

Again, thanks everyone, I'll post back on how it goes. Time to go look for some cypress seeds :)

The folks at NRNTN are personal friends of mine, but I wouldn't really recommend hardly any of the pecan varieties they carry for zone 8 TX. They specialize in selections for northern/midwestern climates - zones 6 and colder.
Womack's would be a better source for grafted pecan varieties that will perform for you there.

WHEN IS THE BEST TIME TO PLANT PECAN SEED AFTER I SOAK THEM---FALL OR SPRING?I HAVE A BUNCH I PICKED UP IN THE WOODS YESTERDAY(OCT. 15,2012)

Forrester,
You can plant them now, and let them stratify naturally - but you'll need to take steps to keep squirrels, mice, voles, etc. from eating them over the winter - raccoons & deer will dig 'em up and eat 'em, too. So...I usually just keep mine in a cool, dry spot(hanging in mesh bags in the barn), then in spring, I'll soak them for a few days and plant - you should get very high germination rates with them.