Not sure if you can classify a J41 or an ERJ 135 as a low cost aircraft....
If you have a look at their current business stratergy Airlink focusses on low density, high yeild regional and domestic routes. Now when the SAA deal drops away their core market does not- so why persue the LLC model when you already have a viable market segment with little or no competition?
The problem Airlink faces at the moment is that they have no Central reservation system, no Departure Control system, no revenue accounting system- and no staff to perform these functions either! Thats what makes their arrangement with SAA so sweet- they just pay SAA to do all this.
Now if they were to go with Virgin then sure they would be given access to all of Virgins' CRS, DCS and revenue accounting functionality but they would still have to employ a few hundred people locally to do all the work plus you then incur all the costs associated with starting a franchise operation- ask Comair about that. Then you have to ask yourself whether the average person flying to Petersburg/Nelspruit/Phalaborwa etc will be tempted to fly more because the plane has Virgin branding? probably not- they will fly whoever operates the route.
If you were to assume( to justify the LLC argument) that they were to start operations on the larger domestic routes then they would have to get bigger aircraft- this market segment is driven by capacity, doesnt seem woth the effort given the number of competitors already in the market...
Here would be my recomendation: Go it alone- go back to the Link brand or choose another name if you like, keep sweet with SAA and do a deal with them to host your flights on their CRS (SAA has hapily done this for years with other airlines- most notably Comair prior to their BA franchise) set up your own revenue accounting department- not too hard to do, get a handling agent to handle check-in and ramp handling (Swissport/ Equity etc) Finally I would outsource the call centre on the same basis as check-in and ground handling- lots of good operators out there at reasonable rates. This stratergy would be quick to impliment- no more than 2 months, it would be cost effective (provided Airlink negociate well!!) and they would probably make more money out of the same passenger base as they would not be paying a cut to another airlink for franchise fees etc.
Anyway my 10c worth.