I'm not sure if things have changed since I purcashed and built my F450 18 months ago, but if I remember correctly the kit does not come with any connectors just bare read and black silicon cable. The choice of connectors is really down to you but XT60's would certainly work. Bear in mind that if the lipos you purchase have different connectors, then you will have to change these. I originally (and still do) used 4mm HXT bullet type connectors on y 450 and 550 because this is what were on my lipos.
As for brand of lipos, I'll probably get flamed here but the turnigy ones are cheap and cheerful and would probably suit your needs. Their 3S and 4S lipos generally come with the 4mm bullet connections and hence my reason for initially fitting these to the F450.
Hope this helps a bit. :02.47-tranquillity:
