you can't just put larger injectors in.... you'll need to retune for it. So, unless you have a full tunable set up/computer ready to go and dyno time booked, it's probably not worth it right now. If you got a leaker, you can probably find a stock injector anywhere for a few bucks. almost all obd d and bseries are 240cc. obd2 will work but use different plugs, so just get obd1 so they plug in.
cams - some cams require adjustable cam gears so they can be set to the recommended spec, ie, +2/-2 per the brand. other's, it won't be necessary. Most will require strong springs and you might as well do the retainers while you're in there too.
This is why most people just go vtec... by the time you spend the 500 ish on the parts to get gsr-ish cam profiles in there, you could have just put a gsr head on the damn thing and had a better flowing top end on there.
If you want to stay non vtec, that's cool too-- just know that the money isn't the motivator.
If you're not building the bottom end (ie, better rods), I'd recommend BC stage2 turbo grind cam or 402t. These turbo grinds generally have higher lift but near stock duration. Gives you like 800 ish more top end rpm of power band over stock and a couple points bump all throughout the power band.
If you are and are going to rev out with the head work and better bottom end, are doing rods, pistons, and oil pump water pump from gsr, etc, and are going to use a turbo that flows some cfm's, using all motor cams has been shown to make big numbers. 404s are making crazy power from 6000 up and have about the same available mid range as stock... It really depends how streetable you want your powerband vs max all out gain against your build standard