What a nice new server software package I found

I searched a lot on the forums all ready (and on Google) but I am still a bit confused so I was hoping to find some answers on the forum.
This is what I have running now:
- AMD x2 4400+ Dual Core Processor
- 1 GB DDR2 Ram
- 2x 1.5TB Samsung EcoGreen HDD
- 2x 1 TB Samsung EcoGreen HDD
- On-Board SATA II controller (up to 6)
- Intel Gbps network interface
On this computer I am running FreeNAS 0.7.2. It works like a charm, but I am looking into having more options available. Because I think with this hardware config I should be able to run more advanced software. Then I heard about Amahi. I read a lot of the website and decided I want to migrate the FreeNAS server to Amahi.
At this moment I have the two 1.5 TB hdd's and the two 1TB hdd's both running in a seperate software raid created with FreeNAS. Both are running software raid 1.
You can imagine my question. Is it possible to hook those hdd's with its current file system (software raid, formatted UFS) to my new Amahi server without formatting them. I don't have a large enough HDD laying around to put the data on temporary.
For the installation of the Amahi software I have a 500GB hdd.
Thanks in advance!
Greets,
Bjorn