Or the Harrier class from the same page. The Harrier has a deck layout schematic and is pretty cool, even if she isn't as sleek or fast as the Hayden. She's even smaller, but carries three phaser strips and two (forward-firing) torpedo tubes (quantum capable)
I like the Harrier design. Whilst most fan designs err towards the all powerful uber-ships, the Harrier seems much more realistic. A small hull designed to be quickly mass produced with the minimum of resources, it is intended to quickly bring ship numbers up after the Dominion War. Most components are stock, so no new manufacturing lines need be set up.
It's well armed for it's (very small) size, four phaser strips, two pulse phasers and a pair of torpedo launchers. One of it's most useful features is the Reconfigurable Mission Module. The RMM is essentially a large cargo bay with added data links and power conduits, allowing it to be be altered for different purposes as the mission requires. Science lab, additional sickbay, extra quarters, whatever.
Due to the limited size and amenities they are intended to be assigned to Starbases, with missions of one to three weeks.