In my opinion you should buy ABI's 3200 Trap or 4000 Trap as these both hybrid systems will give you both qualitative and quantitative applications in one run. Since Trap resolution is 4000 and you can use for qualitative full scan functions and by using QQQ you can quantitate your samples as well.

I strongly suggest you to look at ABI's trap systems and I am confident it will definitely serve your purpose
Massachussetts State Crime Lab uses the 3200 Q-Trap for reasons stated
(QQQ for quantitation, Linear Ion Trap for peak confirmation):

THC & Metabolites: http://www.silvertonesciences.com/files/TI338E.pdf
Opiates: http://www.silvertonesciences.com/files/TI365E.pdf