I also have a TU that features more-or-less realistic maneuver drives.

I get around the pitiful performance (either in terms of thrust or endurance) of such drives by first putting my jump thresholds just a few thousand miles above the upper reaches of an atmosphere. To get there and back from the surface, my ship's use multi-function turbo/ram/scram/fusion jets (a fusion reactor powering first a turbo-fan, then a ram jet, then a scram jet and finally a pure fusion rocket) to get there and back. And - yes - these are pretty much the same engines that Serenity mounts. :)

Only the vacuum stage - the few thousand miles from the upper reaches of the atmosphere to the jump threshold and back - actually consumes onboard fuel (the fuel required for the rest of the journey is covered by using the planetary atmosphere). But even that much is a non-significant amount . . . which I simulate by flipping the LBB fuel requirement calculations between the maneuver drive and the jump drive. This lets me have my "realistic" maneuver drives, yet still use the standard ship designs from the LBBs.  

Of course, this only works if you have an appreciable (better than trace) non-corrosive atmosphere. Which is why people generally only land on and take off from the services of that type of world, since the oddballs require specialised orbital access vehicles.

NOTE: If you decide to go with realistic maneuver drives of significant power, Leonard warned me that the drive exhaust will be - essentially - a continuous, 100-mile-long fusion cannon blast,,capable of vaporizing a city-sized chunk of real estate and irradiating an even larger area. This is the "hard burn" from the Firefly pilot and is also why my drives only switch to pure fusion in low orbit.