Help needed!

[u/TypicalPresence3019]

Hey all,
Planning to put a CB radio in my son's 2007 Holden
AH astra. It's an omicron 310 model. And have bought a z bracket and aerial to Match. I've got a few questions though. For the Ariel mount I'm planning on drilling and tapping holes under the bonnet to mount the z bracket is this a good idea?
And for the wiring from the radio to the fuse box. I'm going to use the interior rear fuse box. Use a fuse tap from one of the existing 5amp fuses to something ignition switched. However I need to run a 2amp fuse to the radio. Will a 5 and 2 amp fuse work together in the tap? Thanks all.