cant see a pic mate?
but for the mods def needs mapping so expect thats your problem.
I would advise against driving it till its sorted, or at the very least keep it off boost and under 3k rpm. Can do catastrofic damage to your engine if maps wrong
Welcome.
Gonna be very different to what your used to :-)
First thing isdecide budget an what you want, classics are more performance over comfort so pretty hard core,new age tend to be a bit more comfortable and toned down. After that few different models to choose from.
VF35 and VF34 are both based on a vf30. VF35 has a smaller exhaust side improving spool but slightly dropping peak, VF34 hs a roller bearing core but retains same exhaust.
35 and 34 have pretty much same spool but vf34 tends to have 10bhp ish more peak, cos of its better peak tends to hold its value better second hand as well as being bigger cost from new
Pretty typical up grade path, as long as you find decent second hand parts you'll be fine.
brakes would be a good upgrade before though, on a wrx they aint great