from what you've said about your bike I reckon you have a German model - I have a Euro version which does not have a Cat or O2 sensor.
The problem you've got is that all the maps on the Dynojet database for your bike appear to be for a bike that has the O2 sensor eliminated (Dynojet eliminator kit US$15 on their website) which probably means that to get everything to work properly you'll have to do the same as I imagine that if the O2 sensor is not removed from the loop it'll be sending all sorts of bogus information back to the ECM to get the mixture adjusted that the PC3
will not be able to deal with...so yes, you'll need to use the eliminator.
Once you've fitted the eliminator kit you should choose a map that is for a bike that is close to your set up - I've found that generally as far as the standard PC3
maps go an aftermarket air filter is an aftermarket air filter and a slip-on is a slip-on - within reason of course...I'm running a map for an Akraprovic slip-on with a K&N air filter on my 954 which actually has an English Viper slip-on with a K&N filter which seems to work really well.
Try starting with map M110-512 - pretty much a standard map which should give you a good reference point. Do some research on construction/design of your slip-on verses the others listed in the Dynojet map database and select one that sounds similar...maybe M110-513 for the Leo Vince slip-on is a close match ?
It's not going to be perfect, and obviously the best thing to do is go and get a custom map made, but if you're like me where spare time is at a premium and facilities are 200Kms+ away some careful research and seat of the testing can deliver some pretty good results.