I didn't really know where to put this, so it looked good here. I am about to order a soldering station and some supplies.

I am wondering what type of solder to get? I am looking at 63/37 and 60/40 mixes but there are still a few options for each.

Also has anyone bought the cheap hong kong deans connectors from ebay? Are they any good?

What size banana plugs do you all run for motor/esc and esc-->batteries?

Genuine Deans are the way to go, the knock offs don't last/stay tight as long and I've had the plastic housings crack.
bullet plugs, 4mm is the most common for 1/10th scale.

+1 - I've had the knock off deans get hot and soft while the genuine ones in the same place get warn, but don't go soft.

I've learned the umbrella type 4mm bullets don't last very long under hard use. I use 5.5mm bullets on 1/8th scale stuff. Will be using 6.5mm bullets on my 1/5th (Baja).

If you have an ESC with posts rather than wires, I'd just run straight wire, no bullets. Solder wire to the motor and then straight to the ESC. It may be a bit less convenient than bullets, but it's a more solid connection and makes for a cleaner wiring job.