I have an SLX crankset and as far as I recall, the bashguard and largest ring are bolted together, the granny is on separate bolts.
This being the case, you will not need new chainring bolts if you intend to keep the bashguard.
If you do not intend to keep the bashguard, then normally you put your ring onto the tabs which previously took the bash, the outermost tabs in other word, except you WILL then need shorter bolts.
If you are going single at the front, then really the Stinger guide is not what you need. Because you are losing the front mech, you will no longer have any retention on the top of the ring. So, you need a full guide, top and bottom.
As mentioned, Superstar ones are ok and fairly cheap, and a BB-mounted one will do you if you don't have iscg tabs. You can get them for working with or without a bash.
I'm not sure if you will need to file your granny tabs but if I recall correctly, the SLX cranks have fairly low-profile tabs and so you may not need to.
You quite often have to faff a bit with spacing the chain device correctly, playing with the spacers behind the BB shell but you can get there eventually.