I currently have Def Tech UIW II's for each channel in a 7.1 set up. I would like to add a pair of in-walls for wides and a pair of in-ceilings for heights and am considering the Invisa series. I do have concerns about timbre matching and the totalling different tweeter designs. Would these Invisa speakers be an ok match with my Def Techs? Would the pivoting tweeter be sufficient to properly project sound for the wide channel if installed on the side walls?

Also, I have two rows of seating at approximately 12' and 17' back from the screen wall.

Thanks for any opinions.

Yep, Invisa would be a great choice, produce a nice big soundfield for your large number of seats. Nope, they won't match the other speakers, but that's probably OK as they are effects channels.

I would suggest Invisa MPX on the side walls (no pivoting tweeter, very wide soundfield), Invisa 650 for height.