Bruno, they have several configs and sizes, but one of the larger (36" wide) is setup for both metric and SAE; and you can see a complete inventory of what that one holds on strictly toolboxes, site here:
http://www.strictlytoolboxes.com/montezuma-toolbox/36-montezuma-tool-boxes-crossover-tool-chest.html
If you look there are other layouts and widths. So hard to imagine not having one that would do the job. Is it perfect? No., Will you still need more storage? I would... BUT, this one in particular would keep my other tool drawers closed 98% of the time...
What it excels at is keeping the most commonly used tools up front and available without fiddling with drawers.
Hmm, lets see if this works: OK not, too bad;
wow, 198 pegs for sockets...:
#TYPENUMBERDESCRIPTION
1Wrenches17 pegsS.A.E. combination wrenches
2Wrenches22 pegsMeteric combination wrenches
3Sockets20 pegs1/2" deep S.A.E. sockets
4Sockets20 pegs1/2" deep Metric sockets
5Sockets15 pegs3/8" deep Metric sockets
6Sockets13 pegs3/8" deep S.A.E. sockets
7Sockets15 pegs3/8" regular Metric sockets
8Sockets13 pegs3/8" regular S.A.E. sockets
9Sockets20 pegs1/2" regular Metric sockets
10Sockets18 pegs1/2" regular S.A.E. sockets
11Sockets32 pegs1/4" regular & deep Metric sockets
12Sockets32 pegs1/4" regular & deep S.A.E. sockets
13Ratchets21 slotsRachet drives & extensions
14Screwdrivers21 slotsScrewdrivers
15Socket tray lifts to access tools underneath
If the Impacts are a deal breaker in the racks, you could probably use someone else's rack(s) in the "under the socket tray" space (15) ...