can't find the right bulb

Be glad to go to the other forum mentioned above, but here's something I thought you should know about. It's got a normal base, not a Mogul base, but it gives 720 lumens at 12 Volts, which in this bulbs consumes only 50 watts. At 790 lumens at 12 Volts, it is fairly close to the light from 1,000 lumens. It is frequently used in marine applications:
https://www.1000bulbs.com/product/607/IN-110050-2PK.html
And it's cheap, less than $2 for a pair.

Also, if your leads are only 15 feet and you are using standard extension cord grade wire, (18 gauge), your lighting will not be affected by the cable hardly at all. If your power source is 12 Volts.

To enable this bulb to be used in a Mogul socket, just get an inexpensive adaptor here:
https://www.amazon.com/MEDIUM-ADAPTER-REDUCER-PORCELAIN-INDUSTRIAL/dp/B0067BOESU

This will allow you to screw a standard size bulb into a Mogul socket.

I will give you a yes to B,C,D. A is a 12 volt or 6 volt auto starting battery. We used 8 to 10 feet of 14 ga. wire on 6 volts or 15 ft of wire on 12 volts. Already have the adapter. Thanks