Not going to tube route, me, not if I can avoid it. I'm just too paranoid and would endlessly replace tubes, thinking that yes, maybe it would change things. Although I have to admit that it is very tempting to add warmth using a tube amp since the AKGs are likely more or less completely neutral, see where it would take me.
Crossovers in movie rigs can be a nightmare but I have nothing but good experiences with JBLs in cinemas and I assume you wouldn't dream of using their lower-end consumer products. Are you doing a 5.1 or a 7.1 setup?
What's always bothers me with home theatre equipment is that it's extremely difficult to ensure the identical handling of all three screen channels. The centre doesn't get the space it needs (usually the speaker is physically placed below the large-screen TV, unlike L & R that both get any space they need, comparatively speaking) so the speaker will always represent a compromise in physical dimensions and frequently in the driver. My Dali speakers are a good example of this. They are great but I don't have three identical screen channels.
My garage setup used to have five identical screen channels, as it handled the old Academy six-channel mag strip setup (5 screen channels, 1 surround) rather than the more recent 5.1 layout, but now that I'm moving to a newer Dolby processor, I'm going to lose the left and right extras. Oh well.
My 5.4 (see how I did that, there?) system is all vintage (mid) eighties hardware (except for one rather large mid/low-bass box - dual eighteens - 2242 JBL) (My LFE is bi-amped). (It is complicated)
I am now using a pair of single 2205/2426/2370/2405 custom enclosures (which I built last summer) for Front L+R - Dual E110/2370/2426/ 2405 For Center - Single E110/2405 for surrounds. So, in theory, they are all voiced to match each other, including the bi-amped sub-bass LFE channel.
(The front lows started out as E140s - a bit middy -, as if I was building a Cabaret style enclosure, then E145 - enhancing the bass-, then "custom" 2235 built on blown E140 baskets-it works per JBL interchangeability chart, finally Stock, ancient, AlNiCo 2205 drivers for the lows up front - best match, yet!)
I have been doing graphs for four months, trying to get the crossover just right. It was OK, at the start, but there is a reason that JBL studio crossovers are so incredibly complex.
Generally, JBL Studio monitors are designed to be used "between near field and far field" for realistic, highly dynamic representation of recorded media in a number of environments, using various room treatments to achieve fewer room nodes or reverberant anomalies within the listening space
(I know I do not have to mention this for your benefit, but for anyone els reading, sound re-enforcement must fill three dimensions- NOT just two).
Mine are not really an attempt to emulate studio monitors. Rather, I am attempting to emulate the cinema sound from my favorite era of movies. Works amazingly well. Interestingly, it blows the modern movie soundtracks up like you HAVE to hear to believe!!
So far, my latest attempt at multi-channel surround in a small living space (sixteen by twenty four by eight to twelve -Cathedral ceilings) fits my needs.
edit: Sorry, I just realized, I put my room dimensions in feet, instead of meters. But, it is a fairly small room for so much sound. You know what that means.
Oh, did I mention, in case I want to "Rock teh House," with music; I can, without worrying if the speakers will give up before the listener does in a game of "auditory Chicken."
OH, incidentally, I do not use tubes in my cinema rig. It is all SS.