Riser card question ... how to make attached card secure?

I've never used riser cards before.. but we have a 2u SuperMicro
server case that has only verticle LP slots for securing the cards
brackets to.. (SC826TQ-R800LPB)..

We were going with the 12 port 3ware 9650SE-12ML pci-e x8 card.. which
only comes in full height.

3ware recommended using this card with an active riser by adex (they
are certified for their cards), rather than 2 seperate 3ware cards due
to possible multilane/motherboard issues..

They recommended cards that are active from adex : http://www.adexelec.com/pciexp.htm

First off, I'm not even sure how i would "lay" this card inside the
system as it wouldnt have a way to be secured.. or do they make riser
cards that could have the bracket secured to the riser card itself?

I'm guessing the best option short of not doing this.. is getting a
flexible riser ribbon card and having the 3ware card lay across the
slots on the motherboard, but this seems risky to me?

Thanks for any tips..

 

Find a case that's made for riser cards.

 

Its a bit out of the question in our case.. i've had an engineer take
a look.. a few standoffs and we will be pretty secure i think.