What I think is the perfect Tau'ri ship (may be a little overkill... )
Class: BC-305 - Achilles Class (Achilles is identical and stationed to guard the Wraith border in Pegasus)
Appearance: BC-304 but twice bigger & polished to be more streamlined.
Crew: ~200 + ~500 passengers (life support for 700)
Primary: 1 Infinity Generator (Extracts energy from a barren parallel universe(Mrs. Miller episode but successful))
Backup: 1 ZPM.
Secondary: 2 Neutrino Ion Generators
Backup: Can drain power from 304's, jumpers, portable naquadah generators or virtually anything on board
Ancient Sub-light engines (same as Aurora class (.999c))
Asgard Intergalactic drive (same as O'Neill class (Earth to Lantia in 4 days)
Ancient Wormhole Drive (capable, never tested due to risk)
Emergency Interstellar hyperdrive (limited speed & range; completely independant from main-systems)
2 primary hangars containing:
2 x 15 F-304 Wasp's (same as 302's but with tiny shield generators protecting the ship against the first few shots, emergency beaming (instead of a chute), a rear rail gun to shoot fighters in chase & missiles replaced by 2 micro-Asgard beam weapon (about 2.5% strength) Designed to fight as a sworm firing at enemy ships with micro-Asgard beam weapons to keep their shields under constant pressure or to provide the power to destroy bombers more easily (such as Al'Kesh).
2 secondary hangars containing:
2x 3 Jumper's v2 (longer than original, larger crew complement, hyperspace capable (limited in range & speed), cloak replaced by phase shifting, Asgard beaming added, 1 mini-Asgard Beam weapon(10% strength) added to the underbelly (comes out to fire))
Primary: 6 Asgard Beam Weapons (one on each side)
Backup: Ancient Drones (replenished using Asgard matter converter)
Secondary: 12 Ori pulse weapons (reverse-engineered)
Backup: 6 Tollan Ion Cannon
Point-Defence: 32 Railguns
Naquadria-enhanced nuclear warheads -> Launched or beamed.
Capable of emitting a directed or omnidirectional wave of energy (such as ARW)
Primary: Atlantian Shield (Imbedded in the infinity generator)
Backup: Asgard Shield (part of the Asgard Core, bolstered by ZPM if main power is down)
Cloak: Ancient Phase Shifting
Guest Area only accessible by 4 bulkheads (front, left, right & rear) and can be completely engulfed in a shield to contain guests.
Force-fields every few meters (just like on ancient ships)
Life sign detectors
Automated turrets in "high-security corridors"
Adjustable artificial gravity (used to immobilise)
On-Board Stargate (with Iris)
Replicator Repair team (like FRAN)
Elevators replaced by transport rooms (like Atlantis)
Current Mission: Explore the Ida Galaxy, find all remains of the Asgard Civilisation for safe-keeping.
Future Mission: Explore other neighbouring galaxies in search for new civilisations.
Potential Mission: Rescue Destiny's crew (based on success or failure of current plan)
To do so the ship would have to perform a series of wormhole drive jumps (jumping from galaxy to galaxy) until they reached destiny. Chances of success are tiny & duration of mission is expected to be several years just to get there.