Cutting the plastics is easy. just take your time and don't rush. Use masking tape or painters tape to mark the lines and make sure you are happy before you cut. Then sand down the cuts to get a smooth finish.
You may as well make a list of what you want, and whenever you have enough money to but something you just cross it off the list.
Trust me, the list will never end. 1 part at a time and you will get there
By the way, nice pipes on your ride.