I would highly recommend NOT putting a gig bag inside a hardshell type case case and checking it. A bass needs the be completely un-moveable in the case to prevent it from getting damaged. It needs to be foamed out to keep the body of the bass from moving around at all in case the case is dropped. The drop is not what usually damages gear, it is the instrument moving in the case and hitting the inside of the case that does the damage.
I think the SKB case would be good, just stuff extra foam or socks around the body of the bass if the stock foam does not properly support the bass.
On anther not, I go back in forth about touring with any bass other than the bass I really want to play. I have decided that to me it is not worth it to be on the road playing a bass I am not in love with while my beloved bass is at home. So now I have everything insured with Clarion Insurance (
www.clarionins.com) They really cover everything a musician would encounter and have policies specifically for musical instruments. I highly recommend it, even though I would hate to have to replace my LG5, it is good to know that if it were lost, stolen or damaged, that I would have the cash to do it
and yes, my bass is now safely back at home

........ until friday when we head to DC!