You can look at the Traxxas 2075 servo's. They are fairly strong. I used them in my "little TMaxx". My "little 1/10 scale" was the same size as my 1/8 scale truggy's. Besides, the TMaxx had bigger tires for it being such a "little truck".
Get what you can afford. If you can afford the Savox then thats what I'd buy. They will last a long time and you can continue to use them in your other vehicles if you upgrade up.
the volcano is not a tmaxx. IT IS SMALLER, i got one for free awhile back and its nothing like a tmaxx.