Even if a datasheet says "VCEO = 20V", derate it to for reliability in RF circuits. The power dissipation (PC) assumes perfect heatsinking; in open air, use only ~60% of the rated value.
For general low-power tasks where 1A is not fully utilized, standard NPNs like the 2N2222 or 2N3904 are easier to source but have much lower voltage limits. Substitution Tips c1124 transistor datasheet better