As the devs mentioned sadly they does not offer unique ship option any more.
I guess your best bet is to find a faction to back you up. Restricted SRP-only ship could be ok since everyone with sufficient RP can get one.
In general the Mod have quite bad history with restricted/personal ships being used unproper in the past. http://discoverygc.com/forums/showthread.php?tid=2783
There are the ship submissions requirements.
If you check the 4.87 credits you would notice that there are bunch of really good ship makers around. My personal advice is to contact Massdriver because based on my humble option he is the best from the modellers around.
However before doing that you should try to find out what exactly you want, considering that cruisers and battleships are off-limits as the devs said you can go for everything from LF up to GB. I suggest to do the ship background first- the reasons why the ship should be in-game, the backup-story, the factions involved, etc.
Some example of really fine ship that is not in the mod for unknown reasons: http://discoverygc.com/forums/showthread.php?tid=81652
(10-09-2013, 10:51 AM)Knjaz Wrote: Official faction players that are often accused of elitism, never deploy them and have those weird, immersion killing "fair fight/dueling" suicidal hobbies. (yes, i've seen enough of those lolduels, where house military with overwhelming force on the field willingly loses a pilot in a duel. ffs.)