Bridge mode for airport extreme or dsl modem? Recomendations?

Question

I'm upgrading to a 'blisteringly fast' 12 Mbps with my local DSL ISP (no cable in my area), and I'm thinking of changing out my
My current, antiquated setup is with a Speedstream 5200 Modem/Router (8 Mbps max) with a Linksys E1200 802.11n router. We have an Apple TV with HDMI into a stout Panasonic plasma, 2 Macs, 3 iPads (2xgen4 + mini), 3 5C iPhones and an old Dell Winbox (XP vintage that I will toss out) that access this configuration in a good-sized house (2 stories, ~4000 sq.ft.).
The Linksys 'n' speed router is somewhat adequate, but we want to do movie/video/music streaming to the AppleTV and we want to buy a new Mac (probably a Mac-mini to replace the Winbox). I also want to future-proof this setup for a few years, given the pain it usually is to do a wholesale swap-out like what I'm contemplating. I want to swap-out this pairing with:
a DSL modem/router to either a Netgear DM111PSP-100NAS (ADSL2+) or an older, but robust Actiontec GT-701D (or the newer -NF).
an Airport Extreme (802.11ac) to manage my Apple menagerie for fast streaming, and also to hang a poor man's network file storage off the USB port.
I'm asking for some recommendations from the community at-large so I can minimize the hassles when I do this swap-out.  Which of the two devices (the modem/router or the AE router) should I put in bridge mode? Any performance penalties one way or another, or hidden gotchas?
Thanks in advance.
Craig

Answer 1

I'm back and wanted to put a coda on this thread.
First of all, many thanks to the recommendations by Tesserax and LaPastenague.  You helped allay my fears in converting over to the Time Capsule environment.
The home network is working just great.  Internal speed-ups all the way around.  TC is working great as both a file server AND a Time Machine site.  The Netgear DSL modem is the firewall and the DHCP server for my network.  As stated in earlier posts, it has superior firewall capabilities compared to the Time Capsule.  I configured the Time Capsule to Bridge Mode with my iPhone 5C, the configuration of which only took a couple of minutes.  The speed between the 802.11 ac devices, my TC and the new Mac Mini, are unbelievably fast--on the order of 150+ Mbps at a distance of 40 feet or so through several walls--beamforming really does appear to work as advertised.  That doesn't matter overall except for the Time Machine aspects, as my DSL line is a blisteringly fast 12 Mbps.
The only glitch I've had over the last 3 weeks was due to a short power outage, and the main problem was the networking with hard ethernet connection to the Time Capsule.  I had to reboot the Netgear modem, as it was in a funky state, while other devices, such as my new Mac Mini, were waiting for the modem to vend a DHCP address.  It turns out that the Apple TV had some persistence with its old DHCP-vended address, and the Mac Mini somehow received its IP address first--which conflicted with the Apple TV.  Now, I'm not sure why the wirelessly networked Mac Mini beat the Apple TV to receiving a DHCP vending first, but it did, and the address persistence of the Apple TV created a conflict on the Apple TV network connection.  Once I realized the problem, I shut down the Mac Mini and made sure all my other devices were off as well.  I then restarted the entire network, the Apple TV received its IP address first, and all was well again.  Granted, I could have disconnected the ethernet and allowed really fast wireless to the Apple TV, but it's only 4 feet away from the Time Capsule, so I might as well have the fastest pipe available for HD streaming to my large-format HD television.
The switchover was absolutely painless.  Both the modem and the Time Capsule took, all total, about 10 minutes to set up and configure.  Much easier than with Winboxes.  Other than the Apple TV IP conflict after the power outage, it's been a real delight.
I'm very happy I switched to this new network configuration.