I picked up a ragged out 2000 Blast for a few hundred bucks several yearsnack. My son and I went through it together then got carried away! We did the 1" PVC spacer on the front fork and CBR rear shock. He liked the taller stance so we added a belt pulley/tensioner as opposed to relocating the mounting holes. Rose the seat hight several inches and gave the bike a whole new attitude! He took it with him to college, it's a great bike for around town.
Looks like you are well on your way to much of the same - thats a very nice airbox delete. There are lots of other cheap mods like rear fender delete and handlebar swap that can really transform the looks.