lol jk DR
first of all, you need to be
to run c6's... I know for a fact that c5's are not (yet) soloable. but here's the low down.
c4's, solo-able in a ship that has 950 dps tank, and 450+ gank with buffer!!!
c5's, solo-able in a ship that has 2000 dps tank, and 750+ gank with buffer!!!
c6's, solo-able in a ship that has 4000 dps tank, and 2000+ gank with GIANT buffer!!!
every site be prepared to stay there for a long time when solo... more dps you have the faster the site and greater the isk/hr... IF you keep it to low # of ppl.
oh and caps... you need 1500+ more tank because of the extra spawns... don't know exact but it's close too...
all sites, more EHP = better survivability (if you can maintain your tank)