You won't be able to fit them front to back, as the light spread is setup so that it spreads out wider widthways, than front to back, as tanks are generally longer than they are deep. If you fitted them front to back you'd probably get dark areas in the middle and either side, and have blinding bright spots on the front and rear glass that'll quickly cover up with algae and constantly need cleaning with a magnet cleaner.
The link bars are good, and while they're expensive for what they are, you won't regret buying them. I have them linking my two 160W razors, and it's not strong enough so that you only need to support the left and right of the now joined unit, I still need to support them in the middle. The bars are only designed for the 120W though, the 160W razor is too long for them to be strong enough.
Looking at your tank, it's similar to mine, I have the Razor's legs on the left and right glass brace, then I've just got a plastic thing in the middle on that middle brace to support them in the middle to avoid sagging.
I'll take a picture of my setup if that'd help?