Hi,
I have asked Graupner what servos could be used for 300 us neutral point signal so the 3 ms and 1.5 ms modes could be used and the reply is:

"Hello,

you CAN use HGM SLP, SOR, SST servos at 1.5ms PPM or 3ms PPM."



http://www3.towerhobbies.com/cgi-bin...?&I=LXEWPE&P=7

This one from Towerhobbies should work.



Tower does not provide specifications but here are from the Graupner.de site:
Specification
Holding torque 6.0V, approx.: 100 Ncm
Transit speed at 6.0 V, approx. : 0,045 Sek/40°
All-up weight, approx.: 43 g
Angular travel incl. trim, approx. : 2 x 45 °
Transit speed at 7.4V, approx. : 0,035 Sek/40°
No-load current drain, approx. : 31 mA
Torque at 6.0V, approx.: 45 Ncm
Holding torque 7.4V, approx.: 120 Ncm
Charging rate at 6.0V approx.: 2100 mA
Dimensions (LxWxH): 40,5 x 19,5 x 25,5 mm
Torque at 7.4V, approx. : 55 Ncm
Bearings: Lager bb2x
Replacement gearbox: 94050.2
Charging rate of 7.4V approx.: 2550 mA
Gear unit: Getriebe mg
Operating voltage : 4,8 ... 8,4 V
Neutralimpuls: 1,5 ms
Max. Ansteuerfrequenz: 2,5 / 400 ms / Hz