you dont need a new fuel rail or a fuel pressure reg, get some dsm 450s and a resistor box, a walbro 255 fuel pump, some arp head studs. Seriously you cant drive that your running your motor extremely lean and detonation is right around the corner. Also I dont care what your air-fuel ratios says, unless you have a wideband o2 sensor the gauge is useless. hondas come stock with a narrowband o2 sensor and putting a gauge on that only makes a light show. When you get the larger injectors let your tuner install them, if your try to install them yourself and try to drive it the car will not even start, because of the size difference, stock are 270cc and the dsms are 450cc. If you want to spend the extra money on 550cc by all means go ahead, but if your on a stock block there is no chance of peaking out the 450cc, You would probably be around 70% duty cycle
I'm not trying to be a dick, I just dont want to see you posting a month from now telling us that you blew your motor and now you got to rebuild it. I would personally stop driving it until you have everything you need to complete it and its tuned, Don't forget your going to need atleast a stage 2 clutch because your stock on will slip. and a catback exhaust, I would also recommend a high flow cat, your going to need to get the air out as fast as your putting it in