Scottish choice of king ?

Hello - wondering if anyone could possibly help. The Act_of_Security_1704 required the Scottish to select a different choice of successor to the Hanoverian line selected by England. Obviously IOTL this was "solved" by the Act of Union. However supposing that this does not occur (and for the sake of argument the Darien Scheme is not carried out), and therefore Scotland does pick a different regal line, who would they pick?

The obvious selection would be the Jacobite claimants but I don't think this would be likely as even in an acrimonious split they wouldn't want to antagonise the English and of course the issue of Catholicism.

How about any one of the illegitimate children of King Charles Stuart II?

http://en.wikipedia.org/wiki/Royal_bastard#Charles_II

Jonathan said:

How about any one of the illegitimate children of King Charles Stuart II?

http://en.wikipedia.org/wiki/Royal_bastard#Charles_II

Click to expand...

Doubt it. It seems to me that the point of the Act of Security was to either force James Francis Edward to convert (not unlike what the Tories wanted to do with Act of Settlement) or to be leverage when negotiating with England. Considering that there was never any official discussion who would succeed Anne, it seemed to be a threat rather than a true attempt to brake the union.