Rebels were all about stealth, whenever possible. No doubt they'd use a ship which was designed for something much less controversial... like your average freighter.
If I recall, there were a few freighters in SW lore... 
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a.k.a.: Grandma Tarkin // hQ.Terrorek
Today's spelling/grammar tip: There = a (sometimes conceptual) place. "There is my car." or "There is such a thing as magic." // Their = posessive. "Their meat is full of worms." // They're = contraction of <they are>. "They're crazy!" // "They're trying to put their shoes up there."