If you go with larger injectors you will need to map for it otherwise you will be putting in too much fuel (the car will think it still has 330cc afterall) so the map needs to be done to scale the injectors appropriately.
Personally, I would leave the injectors until further along your modding journey - do you have any other mods besides the pulley? if not, you can add a dave.f air intake, exhaust manifold (JCM / Janspeed etc), intercooler perhaps a new cat back... I would try to work it so that you can fit a new camshaft at the same time as the bigger injectors and then tune for the job lot
RMW in the states can do remote tuning, not sure if lohen or P-Torque can do this or not.
In summary and IMO - leave the injectors for now and fit the above mods instead. If you can get a set of JCW
injectors you could get a JCW
map flash to keep you going (not sure how great a solution this is tbh) but if you have bigger plans I would wait and do it a little further down the line.