I would say the AP is too nice of a suit to make as a first-time TD. The FX is a great starter suit and you won't feel as bad if you screw up.
I got a FX lite for $385 delivered. I bought an assembled FX lid, then swapped for an RT-Mod, and picked up a pack from a friend for $100. It is the bits and pieces (guns, pouches, pauldron and so on) that will ramp you up.
The FX is the easiest suit I ever assembled.
Here is my suit in the early phase of becoming a Sand Trooper...

My upgraded helmet, my E-11, and my mini-me!

Go for it. Just do not rush... that also gives your wallet a chance to recover too!
John