Servos and batteries for RC tractors

[rangin]

Hi,
In the ebay section of your store, you recommend a number of different components, arduino minis, N20 motors etc which is very useful and thanks for pointing me in the right direction, I have already ordered a number of items.  
But you do appear to be missing a few things from the list, I thinking here of servos for steering and back linkages and a battery to actually run the tractor, is there anything in these areas you would recommend?

Thanks
Rangin

[RC Tractor Guy]

Thanks for the suggestions, I've added the batteries I use the most to the shop and also a couple of servos I've been trying out. Here is the link to the shop. The larger blue batteries swelled out a bit on me but they still work perfectly after many charges since then. I think I might have overly discharged them. The smaller ones haven't done anything strange so far, they seem good.