(haley, feel free to alter any of this to fit, just can't sleep so writing a bit
As a side note, we've referenced the Tokyo class (newest) line of ships, Georgian class (The Valdosta), and the UK class as ship lines that the GAF has employed. I'm going on a limb and saying that the Georgian class has been used primarily in the military sector, while the Toyko and UK class have extended use into the commercial sector as well.
While military and exploratory vessels were the main economic lift to Isely's growth at the start of feasible space exploration, the terraforming of colonies on other planets quickly opened up into a need for commercial and industrial application and ships that could handle the tremendous strains of passenger and commercial transport. The smaller, faster ships used for exploration and by the GAF were simply not outfitted for commercial or passenger use. Isely proceeded to create entire branches of its company dedicated not only to the creation of these types of ships, but also to advancing technology specifically for that purpose. As applicable, technological discoveries there were applied to new lines of GAF oriented ships as years passed; the latest upgrades in inertial dampeners were, in part, taken from progress in the shipping sector as smooth transport of goods was vital for colonial survival and commercial budgets.
Isley's developments in the commercial sector came in two major forms - the first were passenger vessels. The "Metropolitan Line" are small shuttle transports, such as the sort that run from Earth to Alhambra and other short distance shuttle-bus style jaunts; part of this line includes small personal space vessels for the wealthy.
The second class of passenger ship are the "Montreal class" ships, and more recently, the "Tokyo class" ships -these are larger customer transports, though the GAF has adopted the Tokyo class ships with different internal specifications, for several of its newer vessels. Many of the passenger transports out there remain part of the slightly out-dated Montreal line which still function well but lack the Tokyo classes elegance and efficiency. The larger ships sacrificed, just as in real boats, speed and maneuverability for the ability to host dozens if not hundreds of people in comfort. Passenger transports of this size were good for carrying families and large numbers of people with relative ease and comfort to new colonies.
Earth cruise lines like Royal Caribbean, Holland America, Norwegian, and Canard's new endeavors took them into "Space Cruises" also using the Montreal and Tokyo lines - luxury transport vessels similar to ocean liners. "Space Cruises" toured from Earth to Alhambra to various close "solar system" colonies, offering passengers a chance to see the stars.
The other form of commercial ship that Isley developed was for commercial transport. As colonies grew and expanded, the need to transport goods both to and from Earth increased into a booming business. Two lines of ships were developed for this: The first, the Cairo class were larger cargo ships. Their sister ships - the UK line - were marginally sleeker and more manueverable and used as GAF military vessels. For the GAF, the UK vessels were tanks, sacrificing speed for near invulnerability and while useful in the skirmishes, they were also useful in exploring new planets, asteroid fields,and for hosting large crew complements. In the commercial sector, the similarly engineered Cairo class were the work horse of space, obligingly hauling cargo long distances with relative speed and safety. The second class of transport line was smaller and designed both for smaller shipments but also shorter distances between solar-system planets; this, the "Melbourne class" had similar layouts to the Cairo line but on a smaller scale and were popular with smaller businesses needing to get their goods to larger points of transport.