What kind of tires do you have? The mods you have now and decent tires should be 13's easy. A larger MAF will net you another 5hp maybe, pulleys will gain you some decent power, what about the free mods? If you are running decent gas you can advance the timing or some more power. I ran 13.74@103 with the mods you have an pulleys in a '88 LX. This was with some 245/50 Nitto on Pony rims.
As far as a supercharger, used anywhere from $800-2000 and new $1900-4500, depends on the kit. I am listing one on here soon that came off my 93 LX that will be a great deal for someone.
With 5-8lbs of boost you can get away running the stock 19lbers and FMU for awhile until you can upgrade the injectors and MAF size.
With my 93 GT I ran 13.80@100 with stock motor, 3.27 gears,pulleys,and exhaust. I added a Powerdyne 9lb kit and changed nothing else and ran 12.77@111. That was untuned with the FMU and 19lbers still. So it was a huge gain for the small amount of time it took to install.