I am re-entering RC after a 25 year absence. What a wonderful but bewildering array of new equipment.

My new Futaba 7c didn't come with a Rx battery pack so the Hobby shop sold me a 6v NMIH. The charger that came with the radio is a 4.8v so I need to buy a separate charger. I can spend $8.00 to $130 for this item - thus my questions. I will now have 3 different battery types to deal with - Nicad, NMIH and lead acid (field box). I will by flying 40 size glow A/C but could warm to the idea of electric flight at some point which would add a 4th variety to the mix.

1. How do you check the charge status of your receiver battery pack in the field? I used to rely on the old expanded scale voltmeter....
2. Can I use the power panel on my field box to quick-charge the NIMH or am I better off buying back-up battery packs for those long days of flying?
3. Should I spring for one of the new do-it-all battery chargers or is that not needed until I get into electric flight?

Thanks for the input.

Bruce