I made a thread about this (which I can't find using the new forum search doodad) a while back...
The concensus seems to be that the Taipan is the best "newbie" ship for SLF jockeys but then, once they rank-up, there are better options.
The Taipan is pretty tanky and is a solid ship for any level of SLF pilot.
Low-ranking pilots in the GU97 and Condor seem to get splatted really quickly but if you let a Deadly/Elite pilot loose in them, they can be seriously useful.
As for the Guardian SLFs, same thing applies but, also, the "worst" of the Guardian SLFs (the XG7, IIRC) is actually the best.
I forget the details but, if you compare the stat's of all the Guardian SLFs, 2 of them have obvious apparent strengths and one seems significantly worse.
In reality, however, it seems like the "better" GSLFs aren't much use while the other one is.
Personally, I'd suggest sticking with the Taipan at least until the pilot reaches Deadly rank and then swap to a Condor or an XG7 (assuming that's the GSLF I'm thinking of).