I am searching for a new board for an upcoming FREERTOS project. Do you have any familiarity with these vendors ? Do you have any preferences from the list provided ?

___________________________________________________MMU____Ghz_RAMStorageUSBEthernet__Video DreamPlug
( Marvell's Kirkwood 88F6281 ARM9E SoC) yes 1.2 512MB 4GB, SATA 2 1000 N/A

Udoo Freescale i.MX6 SOM Quad (ARM Cortex A9) yes 1.2 1G SATA 4 1000 XGA, WXGA Intel Quad Core yes 2.56 8G 32G, SATA 3 1000 HDMI

Intel MinnowBoard Max Intel Atom E3826 yes 1.46 8G SD card, SATA 2 1000 microHDMI FTDI cable sold seperately.

odriod C2 Amlogic Quad Core Cortex-A53 64 Bit ARMv8 yes 2 2G Micro SD 5 1000 HDMI

HummingBoard yes
Freescale i.MX6 SOM Quad (ARM Cortex A9) yes 1.2 1G SATA 4 1000 XGA, WXGA Freescale i.MX8 SOM Quad (ARM Cortex A9) coming soon

Solid-Run HummingBoard ? from SOM micro SD, mSATA 2 from SOM from SOM
Freescale i.MX6 SOM Quad (ARM Cortex A9) yes 1.2 1G or 2G SATA, Micro SD 4 1000 HDMI camera interface Intel Pentuim Quad Core (MicroSoM IB3710) yes 1.6 4G 4G, SATA, Micro SD 4 1000 HDMI

You are inexperienced I guess, so start with something simple. Buy a STM DIscovery board like http://www.st.com/content/st_com/en/products/evaluation-tools/product-evaluation-tools/mcu-eval-tools/stm32-mcu-eval-tools/stm32-mcu-discovery-kits/32f411ediscovery.html

or http://www.st.com/en/evaluation-tools/32f746gdiscovery.html

http://www.st.com/en/evaluation-tools/stm32-mcu-discovery-kits.html?querycriteria=productId=LN1848

suggest you start with a STM32F4.... series first

buy them everywhere $16+