NIStune can do the job just fine. If you really want to ditch the MAF then something like Haltech or Link can support a speed density setup. Do you have any budget constraints to consider? NIStune isn't really power limited necessarily until you start approaching 4 digit horsepower and even then it's more about certain features and safety limits you would want access to. NIStune can also support flex fuel like other standalones.
1992 300ZXTT -BPU 1987 300ZX Turbo 545 RWHP & 540 RWTQ On The Dyno
"Ahh, to have the pos 323 appreciated by a 30k evo owner." -SactoTodd