http://www.cyclone.com/products/expansion_backplanes/index.php
http://www.cyclone.com/products/expansion_systems/index.php
Yes, I will make you a good deal for your help. Of course, they are 20% off thru the 21st.
Is there a technical requirement for using PCI-E instead of PCI? (PCI expansion is much much cheaper)
How high are the modules? (you could use PCI -> PCI-E adapters in a 4U chassis and still save wrt Magma - or buy only the backplanes and expansion adapters)
Dell has a very interesting chassis too.
PCIe motherboards with required number of slots are more available.
We are looking into the cyclone's above.
You can easily find PCI boards for 1/4th the price of the MAGMA, including housing. It goes down to about 1/10th if you mix and match PCI and PCI-E and limit yourselves to about 9 slots expansions. There are also 2 and 4 PCI-E expansion boxes that are pretty cheap, but heat venting might be an issue (small boxes). What's the planned TDP for the modules?
If power is an issue and you need to design your own enclosure, you can always source the backplane + adapter only from MAGMA, which is about 40% of the full enclosure price AFAIK. Add about 800USD for a custom enclosure (less if more units) and about 200-300 for a 1500W PSU Gold/Platinum and you're still at 50-60% of the initial MAGMA price.
The Dell option might be useful for a rush order or prototype testing, depending on availability on their end. Nothing to customize, just PnP. I believe that with 3600W you should have enough power