Hello.
I advocate OBD1 conversion and open source boost code, it can be done quite cheaply if you have a DIY bent - cheaper than an AFC. 99 Si's and Vortech blower kits strike me as a pretty $bling$ setup, so even if you have to pay a few dollars it's not a bad thing, and won't run much more than an AFC.
If the Vortech setup is intercooled you should be alright with AFC hack, but I dislike blowers as they heat charge air more than a turbo. That, plus timing issues, makes it a little more volatile than what poor kids with rusty LS powered CRXs have done with the AFC hack in the past.