I think the rtr kit comes with a battery and slowish charger. If you get it, try it out for a couple of runs using the full battle life, that will guide you towards how many / size of spare batts you need. The brushed version prob comes with nimh batts, and unless you are going to upgrade to brush less, keeping it simple and sticking to the same battery type won't hurt the bank too much.
I have seen varying reviews of the vantage, some like it, others think it breaks too easily. I have the carnage which is v similar and yes it does break if you hit stuff hard, but parts at the moment are reasonable.
As for charger, somewhere in the 40 quid region you should find a charger that will do everything you'll ever need in a reasonable amount of time. Eg I use the over lander rc-6s AC which I can use to charge car battery and transmitter batteries.
One last point, if you can squeeze the budget, you might be abke to get the brush less version which comes with lipo battle and 2.4 ghz radio. This combo will be faster, better battle life and less likely hood of radio interference but has the higher price tag.