Going to sound contrary to everyone else, but....
...I'd stick with your 130slt for a bit longer and get your money's worth
the 5" reflector is a perfectly decent scope and will show you plenty of the bright stuff, and those are the best objects when you get started. Sure a 8" Dob will be brighter and show you more detail...but your SLT has tracking and that's worth more IMO....it's easier to see detail when it's stationary and you can concentrate on it rather than trying to keep an eye on it and keep nudging the scope to keep it in the FOV.
Just my IMO, all these other guys have got a bad case of aperture fever...we all have...just fight it as long as you can
