Yes, the small powerpole distribution block would work well. I am doing just that for my HF and VHF/UHF rig and antenna controller in my truck. something like this would work for you. https://www.amazon.com/Position-Distribution-Powerpole-Connectors-PD-4/dp/B071LHY6MV
The combination of the IC-705 and the 100 watt amp will draw a peak current of around 25 amps on voice SSB and CW.If you run 15 feet of 10 gauge wire to the battery positive terminal, the peak voltage drop on that piece of wire will be around 0.4 volts. The fuse and the ground connection will probably add another 0.2 volts or so of peak drop. So at peak current draw, plan about a 0.6 volt drop. Most radios and amplifiers will handle this as the running voltage will be 13.8 volts putting you at 13.2 volts on peak current draw. So as James stated, get rid of the power supply and stop plugging the 705 into the inverter. Connect everything to the new wire to the battery. Put a 40 amp fuse at the battery on this positive wire.I operated 100 watts from my Yukon for many years. I didn't want to run a new wire so I took a slightly different approach. I put everything in the back of the vehicle (remote head to the front) and plugged everything into the 10 amp accessory socket in the back. But I added a standard AGM battery directly across the 12 volt outlet. This battery would handle the peak current draw of the radio (voice SSB) and would automatically be charged while the vehicle is running and the radio didn't demand the peak amps. The 12 volt outlet shut off when the ignition was turned off so I didn't need to worry about one battery draining the other when parked. There was no need for any additional circuit as the voltage drop in the Yukon wiring harness automatically gave priority to the added battery when the current demand was high. Don't attempt to operate the radio for an extended period when the vehicle is turned off or the start-up charging current may open the 10 amp fuse.A more modern approach to my Yukon method is to substitute super capacitors for the added battery. This takes a little more surrounding circuitry to properly manage the charging of the super capacitor bank but it does a great job of shaving off the peak current demand.- Glenn W9IQ
WOW!And you haven't even begun to address the antenna issues yet if you want to go HF
