where should i start with modding?

[scheides]

Generally people mount the boost gauge on the A-pillar, to the left of the steering wheel. As far as bang for your buck goes, I'd do 5 things, in this order: K&N filter/cut stock air can, boost gauge, mbc (15psi), walbro 255hp fuel pump (now mbc@19-20psi), 3" turbo back exhaust.

If you shop around, you should be able to get that done for well under $1k and you'll have a fun DD on your hands. #1 rule is to NOT skimp on ANYTHING, as you will end up paying for it later.