I am not aware of any studies on the potential partner preference of aspies, but I have seen a study about shy people. Shy people show a clear preference for beautiful people as their potential partners in comparison with non-shy people.
I'm willing to bet a small sum on aspies reacting in the same way.
Why? Because, infamously, aspies don't have the best social skills (shy people may not lack social skills but the end result is similar). Lets look at the two directions one at a time:
1. An aspie looking for a date: he is probably less aware of the social status, thoughts, character, mind of his various potential dates than the average NT. But he still has to choose (consciously or unconsciously) who to approach. Since the 'internal' data is not easily accessible, it seems likely that external features (ie. looks) will get a relatively higher weight.
2. The aspie as a potential date for someone else. A fair number of aspies have serious trouble approaching potential dates for various reasons (high anxiety, low self esteem, low social skills are common ones). Thus many relationships are initiated by the other person. Good looks come to play again because the usual highly valued date characters (confidence, sense of humour etc.) may not be easily observable even if the aspie has them.
This is, of course, just a wild hypothesis, and equally obviously not going to be valid for everyone even if it were statistically significant. Any particular person can have all sorts of preferences ranging from a demand for classical beauty, to being totally disinterested in the looks of a partnes, to an actual fetish for ugliness. You get all sorts 