TrueHD and DTS-MA 5.1

[Brakboy]

I'm trying to get a new surround sound system to accomedate my Blu-Ray player. I have run into a confusing situation.

So that i did not "overbuy" a new AV receiver, i started paying more attention to what most action Blu-ray's offer for the audio and noticed something surprising... Most offer True HD and DTS-MA 5.1 instead of 7.1.

Im confused because i cannot locate and good brand that has a 5.1 system with these codecs... they are all 7.1's.

I have searched all of YAMAHA, ONKYO, and SONY... although i dont think i go for a sony receiver.

Is this just a money scheme or will more studios start utilizing 7.1 on a regular basis.