Can a tank be too large for seahorses

I just bought a 60 gallon tank, the whole set up, and I am planning on
buying a few sea horses, from what I have read from oceanrider.com, the
tank bred sea horses will easily feed off frozen shrimp, is 60 gallons
to large for only 4 or so mustang seahorses? can I combine different
kinds of seahorses i.e. zulu's and sunbursts and mustangs? will they
court with the different species of seahorses? Can I also put some 2
clownfish in the tank with the seahorses? what kind of vegitation
should I get, and is there any live coral that does well in a tank with
low circulation ( as I have read seahorses like calmer slow moving
water) Is the live coral okay with the seahorses? Are there any other
fish that do well with sea horses? Basically anything will help me out.