Personally, I'd recommend any of the Luftschiffbau Zeppelins. There's one in Arsenal and two in Unfriendly Skies.
if you don't plan to Chameleon Coat it, I'd recommend on taking the 2053-C (from US) since it has both the highest Body score (thus most cargo room) and comes with Improved Economy and Sun-Cell mods pre-installed.
If you do plan on using Chameleon Coating on it, then use the LZ-2065, since you can't use Sun-Cell and Chameleon Coating and it has the second-highest Body score... just be aware that you'll have to stop to refuel eventually.
In either case, slap in an Amenities upgrade... and Chameleon Coating, Improved Economy and an extra Fuel Tank if you go for the LZ-2065... and you've got well over 20 (over 30 for the 2053-C) points of Body to play with for other upgrades.
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As for whether it's worth it to take the SunCell over the stealth... well, that depends on how the GM rules that SunCell works with the Operating Time boosts provided by Improved Economy and Lighter Than Air.
Base is 6 hours, and Sun Cell states that it recharges 1 hr of OT per 2 hours, up to half capacity (in this case, 3 hours). However, IE and LTA combine to turn that 6 hours into 120 hours by reducing how much energy it uses.
Logically, since the increased OT comes from reduced fuel expenditure, that means Sun Cell should be providing 20 hours per 2 hours, up to 60 hours... essentially, allowing the Zeppelin to run indefinitely. However, the rules for Sun Cell say nothing about adjusting for things like Improved Economy, which would mean you'd still have to land and recharge every week or two as power drains away overnight.